Vietnamese-English False Friends: The Complete List for Vietnamese Speakers

1Why Vietnamese produces false friends other languages don't

A false friend is a word that looks or sounds like a word in your own language but means something different. Most learners meet one kind of false friend. Vietnamese speakers meet three, and they come from three different centuries.

The first layer is French. Vietnam was under French administration for roughly seventy years, and the language absorbed hundreds of everyday words: the word for a shirt, a tie, petrol, a train station, a backpack, soap, cheese, a screwdriver. Those French words also travelled into English, but they landed in a different part of the English vocabulary, usually higher, older, or narrower. So the Vietnamese word is completely ordinary and the English cousin is not.

The rule: a word that came into Vietnamese through French is almost never a safe bet in English. The English word usually exists, but it is formal, technical, archaic, or about something else entirely.

The second layer is Vietnamese-made English. Since the 1990s, Vietnamese has coined its own English: hot girl, seeding, auto, check var, PR, fan cung. These are real Vietnamese words made from English parts. They are used constantly in Vietnamese media and by Vietnamese speakers of English, and native speakers do not recognise them.

The third layer is the ordinary kind, where a Vietnamese word covers a range that no single English word covers. Nho means both remember and miss. Thuong means love, care about, and feel sorry for. Hoc means both study and learn. These are the hardest, because there is no wrong-looking word to catch. The sentence is grammatical. It simply says something you did not mean.

Tip: Sort your own errors by layer. French-loan errors are fixed with a dictionary. Vietnamese-made English is fixed by learning the real English phrase. Range errors are fixed by learning which English word covers which part of the range, and that takes examples, not definitions.

2The French layer: words that reached Vietnamese before they reached you

These are the words most likely to appear in a Vietnamese speaker's English without warning, because in Vietnamese they are completely neutral. The English relative exists, which is exactly what makes it dangerous: nobody corrects you, they just look confused.

so mi is not a chemise

Vietnamese so mi comes from French chemise and means an ordinary button-up shirt, the thing you wear to an office. English chemise means a woman's loose undergarment or slip. Say I bought a new chemise for the interview and you have said something you did not mean. English: shirt, or dress shirt.

ca vat is not a cravat

Vietnamese ca vat comes from French cravate and means a necktie: the standard item every man wears with a suit. English cravat means a wide, old-fashioned neck cloth worn instead of a tie, and sounds either historical or affected. English: tie, or necktie.

com le is not complete

Vietnamese com le comes from French complet and means a men's suit. English complete is an adjective meaning finished or whole. He wore a complete to the wedding is not a sentence English speakers can repair. English: suit.

xang is not essence

Vietnamese xang comes from French essence and means petrol. English essence means the core quality of something, or a concentrated extract like vanilla essence. I need to buy essence sends someone to the baking aisle. English: petrol in British English, gas or gasoline in North American English.

ga is three different words

Vietnamese has ga from French gare, a train station; ga from French gaz, cooking gas; and ga from French drap, a bed sheet. English keeps these completely separate and none of them is called ga. English: station, gas, sheet. Context will not save you here, so learn the three separately.

ba lo is not a ballot

Vietnamese ba lo comes from French ballot and means a backpack. English ballot means a voting paper. English: backpack, or rucksack in British English.

may o is not a maillot

Vietnamese may o comes from French maillot and means a sleeveless cotton undershirt. English borrowed maillot too, but it means a one-piece swimsuit, and even then it is a fashion-magazine word. English: vest in British English, undershirt or tank top in North American English.

lo cot has no English relative at all

Vietnamese lo cot comes from French blockhaus, a concrete bunker, but modern Vietnamese uses it for the metal barriers around long-running roadworks, and by extension for the roadworks themselves. There is no English word that does this job. English: roadworks in British English, construction or a construction site in North American English.

phanh, from French frein, is a brake, not a French verb you can use in English
vo lang, from French volant, is a steering wheel; English volant is an archaic word meaning flying
xa phong, from French savon, is soap; there is no English savon
bit tet, from French bifteck, is a steak, so do not say beefsteak, which sounds dated in English
pho mat, from French fromage, is cheese; English has no fromage outside a menu
giam bong, from French jambon, is ham; English jambon appears only on French menus
tuoc no vit, from French tournevis, is a screwdriver
cui dia, from French cuillere, is a spoon
o to, from French auto, is a car; in British English auto is not a noun for a car at all
bo, from French beurre, is butter, and confusingly qua bo is an avocado

The avocado one deserves its own warning. Because bo covers both butter and avocado, Vietnamese speakers regularly produce avocado butter, butter juice for avocado smoothie, and I ate butter with bread when they mean exactly that, and it is correct, and the listener is unsure which one you mean. Add the word: avocado smoothie, butter on toast.

Tip: If a word feels French inside Vietnamese, look up the English before you use it. Ninety per cent of the time the English word exists but is rarer or narrower than you expect.

3Vietnamese-made English: words that sound English but aren't

These are made of English parts, used constantly in Vietnam, and unrecognisable to a native speaker. They are the hardest layer to notice, because they feel like English you already know.

hot girl and hot boy

In Vietnamese these are ordinary nouns meaning an attractive, usually young and internet-famous person, and they appear in newspaper headlines. In English, calling someone a hot girl is crude, and hot boy is not English at all. Say influencer, model, or if you mean famous online, internet personality.

seeding

In Vietnamese marketing, seeding means paying people to post positive comments and reviews. English seeding means planting seeds, or distributing a file, or assigning positions in a tournament. To describe the practice in English you need a phrase: paid comment marketing, astroturfing, or seeding a discussion, which still needs explaining.

auto

Vietnamese internet slang uses auto as an adverb: auto thang means will definitely win, auto tin means obviously believable. English does not use auto this way. Say automatically, definitely, or guaranteed.

check var

From football's VAR system, Vietnamese uses check var to mean go back and verify what someone claimed, usually by finding an old post. English speakers do not use this. Say fact-check it, or look it up.

PR as a verb

Vietnamese uses PR as a verb meaning to promote or to hype something, including yourself: no dang PR cho quan moi. In English PR is a field of work, not something you do to a thing. Say promote, plug, or advertise.

training and other verbs made from nouns

Vietnamese uses duoc training, duoc support, duoc confirm. In English these need real verbs: I was trained, they supported me, please confirm. Using the bare noun with be sounds like a machine translation.

fan cung is a hardcore fan or a superfan, not a hard fan
hang sida means second-hand clothes in Vietnamese, from aid shipments, and the English word it comes from means AIDS, so never use it in English at all; say second-hand or thrifted
chill in Vietnamese describes relaxing music or a relaxed place; English chill is mainly a verb, so say relaxing or laid-back
trend as an adjective, rat trend, is not English; say trendy or on trend
combo is safe for food but not for a general bundle; say package or bundle
sexy in Vietnamese can mean simply stylish, and in English it does not
OT is understood in Vietnamese offices but say overtime in English
teamwork used as a countable noun, we have many teamworks, should be group projects or team tasks

Two of these can genuinely damage you. Hot girl on a CV or in a professional email reads as crude. Hang sida in English is incomprehensible at best and offensive at worst. Remove both from your English vocabulary entirely, not just from formal English.

Tip: Test any English-looking word you learned in Vietnam by searching it in quotation marks together with a plain English word. If almost every result is a Vietnamese site, it is Vietnamese, not English.

4The complete one-to-one false friend list

Quick reference. Left of the arrow is what a Vietnamese speaker usually means; right of the arrow is the English word that actually carries it.

so mi, meaning a shirt, is not chemise, which is an undergarment. Use shirt.
ca vat, meaning a tie, is not cravat, which is an old-fashioned neck cloth. Use tie.
com le, meaning a suit, is not complete, which is an adjective. Use suit.
xang, meaning petrol, is not essence, which is a core quality or an extract. Use petrol or gas.
ga, meaning a train station, is not gas. Use station.
ba lo, meaning a backpack, is not ballot, which is a voting paper. Use backpack.
may o, meaning an undershirt, is not maillot, which is a swimsuit. Use vest or undershirt.
vo lang, meaning a steering wheel, is not volant. Use steering wheel.
lo cot, meaning roadworks, has no English cousin. Use roadworks or construction.
hot girl, meaning an online celebrity, is crude in English. Use influencer.
seeding, meaning paid comments, is not English seeding. Use paid comment marketing.
auto, meaning definitely, is not English auto. Use definitely or automatically.
PR as a verb, meaning to promote, is a field of work in English. Use promote.
actual is not actually current in English; Vietnamese thuc te maps to in fact or actually, while current or up to date is what you usually want.
sympathetic does not mean nice or friendly; it means feeling sorry for someone. Vietnamese de men is friendly or likeable.
sensible does not mean sensitive; it means practical and reasonable. Nhay cam is sensitive.
eventually does not mean possibly; it means in the end. Co the is possibly or maybe.
assist means to help, not to attend. Tham du is attend.
library is not a bookshop. Nha sach is a bookshop; thu vien is a library.
college in North American English is a university, not a two-year school as in Vietnamese usage of cao dang; say community college or vocational college.
professor is a specific senior university rank; a teacher at any level is a teacher, and at university a lecturer or instructor.
control does not mean check or inspect; kiem tra is check or inspect, and control means to have power over.
engage does not mean to hire; tuyen dung is to hire or recruit.
propaganda is always negative in English; tuyen truyen in official Vietnamese is neutral, so use public information campaign or outreach.
cadre sounds military or communist in English; can bo is better rendered as official, staff member, or civil servant.
solve is not the same as handle; giai quyet covers both, so choose solve for problems and handle or deal with for situations.
discuss takes no about: discuss the plan, never discuss about the plan.
recommend, suggest and propose do not take an object plus to-infinitive: recommend that you go, not recommend you to go.

Tip: Do not try to memorise this list end to end. Read it once, then come back after you have written something in English and check the words you actually used.

5Nho and thuong: the feeling words that have no single English word

This is the layer no dictionary fixes, because the dictionary gives you two English words and no way to choose between them. These sentences are grammatical. They simply say the wrong thing.

nho is both remember and miss

Toi nho ban can mean I remember you or I miss you, and Vietnamese does not force you to choose. English does. I remember you very much is not English. I remember you means I have not forgotten who you are, which is almost cold. I miss you means I feel your absence. Choose deliberately every time.

thuong is love, care, and pity at once

Thuong covers the warm affection a parent has for a child, the care you feel for a friend in trouble, and the pity you feel for a stranger. English splits these across love, care about, feel for, and feel sorry for, and feel sorry for is condescending. I pity you, translated straight from thuong, is close to an insult. To a family member say I love you. To a struggling friend say I really feel for you.

buon means sad, but its compounds do not

Buon alone means sad. Buon cuoi means funny. Buon ngu means sleepy. Buon non means nauseous. Buon chan means bored. A learner who has learned buon equals sad will produce sad-laughing for funny and sad-sleep for sleepy. Learn each compound as a separate English word; the sad part does not transfer.

ngai has no English equivalent

Ngai covers shy, embarrassed, reluctant, and the specific feeling of not wanting to trouble somebody. Toi ngai lam phien becomes I do not want to bother you, not I am shy to bother you. Which English word you need depends entirely on the situation, so translate the situation, not the word.

hoc is both study and learn

Study is the activity, whether or not it works. Learn is the result. Toi hoc tieng Anh ba nam is I have been studying English for three years, describing effort. I have learned English for three years is wrong, because learn is not something you do for a period. Rule of thumb: you study a subject, you learn a fact or a skill.

biet is both know and can

Toi biet boi is I can swim, not I know swim or I know how to swim in most contexts, though I know how to swim is acceptable. With languages, English strongly prefers I speak Vietnamese over I know Vietnamese.

Tip: For every one of these, write two English sentences that mean clearly different things, and label which Vietnamese situation each one belongs to. One word with two glosses will never stick; two sentences with two situations will.

6Collocations translated word for word

These are the most recognisable Vietnamese-English errors, and the most quickly fixed, because the words are right and only the pairing is wrong.

mo den, open the light, is turn on the light; tat den is turn off the light
mo TV, open the TV, is turn on the TV
an com, eat rice, usually means have a meal, so say have lunch or have dinner unless rice is the point
uong thuoc, drink medicine, is take medicine
di giay, go shoes, is put on shoes or wear shoes
doi mu, wear a hat by a different verb, is still just wear a hat in English
cat toc, cut hair, when a barber did it, is get a haircut or have my hair cut; I cut my hair means you did it yourself
rua mat, wash face, is wash my face, with the possessive; English needs my, not the
danh rang, hit teeth, is brush my teeth
lam bai tap, do homework, is do homework, which is one of the few that transfers cleanly
choi the thao, play sport, is play sports or do sport, never make sport
hoc bai, study lesson, is do my revision or study for class
chup anh, take photo, is take a photo, with the article
nghe dien thoai, listen to the phone, is answer the phone
xem gio, watch the time, is check the time
an tiec, eat a party, is go to a party or attend a reception
an cuoi, eat a wedding, is go to a wedding
an anh, eat photo, meaning photogenic, is photogenic
noi doi, speak lie, is tell a lie or lie
keu taxi, call a taxi, is fine, but bat taxi, catch a taxi, is also fine in English, so this pair is safe

The deepest version of this problem is lam, which covers both do and make. Vietnamese has one verb where English has two, and the split is not logical. You do homework, work, business, your best, the dishes, and a favour. You make a mistake, a decision, a mess, an effort, progress, a phone call, and money. There is no rule; there is only the list. Print it and keep it where you write English.

Tip: When you catch one of these in your own speech, do not just note the correct version. Say the correct version out loud in three different sentences straight away. Collocation errors are motor habits, and they are unlearned by repetition, not by understanding.

7Numbers, dates and money: the punctuation Vietnam inherited from France

Vietnam writes numbers the French way. English-speaking countries write them the opposite way. This is not a style preference; it changes the value of the number, and it goes wrong most often in the documents where it matters most.

In Vietnam, 1.000.000 is one million and 12,5 is twelve point five. In English, 1,000,000 is one million and 12.5 is twelve point five. The comma and the period swap roles completely. Write 12,5 in an English document and a careful reader sees twelve point five and a careless reader sees twelve thousand five hundred.

Dates flip too

Vietnam writes day first: 03/11/2026 is the third of November. The United States writes month first: 03/11/2026 is the third of March. Canada and the United Kingdom are inconsistent, which is worse. In any document that crosses a border, write the month as a word: 3 November 2026, or November 3, 2026. Never rely on the numeric form.

Vietnamese big-number words

Vietnamese nghin is thousand, trieu is million, and ty is billion, and these line up with English exactly, which is good news. But nghin ty, thousand billion, is what English calls a trillion, so convert rather than translate. And Vietnamese speech often drops the unit, so hai muoi ba can mean twenty-three thousand in a market; in English always say the unit.

Money

Vietnamese dong amounts are large, so people say numbers in units of thousands and speak in short forms: hai lam k for twenty-five thousand. English has no k in formal writing. Write 25,000 VND, or in speech twenty-five thousand dong. And when converting for an English reader, give both: 25,000 VND, about one Canadian dollar.

On a job application, an invoice, or an exam answer, a swapped decimal separator is not a small error. It is the kind of error that gets a form rejected without explanation. Check every number in any English document you send.

Tip: Set your computer, your phone and your spreadsheet to English formatting when you work in English. Fixing this at the tool level removes the error permanently, which no amount of care will.

8Grammar transfer that turns into vocabulary errors

Vietnamese grammar is very different from English grammar in ways that surface as word choice rather than as obvious grammar mistakes. That is why they survive so long: they do not look like grammar errors.

The missing to be

Vietnamese uses la only before nouns, never before adjectives. Co ay dep is literally she beautiful, and it is perfect Vietnamese. So Vietnamese speakers produce She beautiful, I very tired, The weather cold. English requires the verb: She is beautiful. I am very tired. The weather is cold. This single pattern is the most recognisable marker of a Vietnamese speaker's English, and fixing it changes how fluent you sound more than any vocabulary work.

Tense marked by time words, not by the verb

Vietnamese marks time with words like da, dang and se, and the verb never changes. So Yesterday I go to school feels complete. English marks it twice, once with the time word and once with the verb: Yesterday I went to school. When you have a time word in the sentence, that is your reminder to change the verb, not your excuse not to.

No plural s, and classifiers instead

Vietnamese does not add anything to a noun for plural; number is either obvious or carried by a separate word. This produces many book, three student, a lot of information about the plans. Get the plural right first and articles second, because a missing s is more noticeable than a missing the.

Articles, which Vietnamese does not have

There is no a, an or the in Vietnamese. Learners either drop them, giving I am student, or over-insert them, giving the life is hard. Two rules cover most cases: use a or an the first time you mention a countable thing, and the after that; and do not use the with general plural or uncountable nouns, so life is hard, not the life is hard.

Very, from rat and lam

Vietnamese intensifies constantly with rat, lam and qua, and it does not sound excessive. Translated directly, English becomes very good, very beautiful, very delicious in every sentence, which sounds childlike. English prefers a stronger single word: excellent, gorgeous, delicious already contains very tasty.

Topic-comment order

Vietnamese fronts the topic: Quyen sach nay toi doc roi, this book I already read. English can do this for emphasis but it is marked and slightly literary. Default to subject first: I have already read this book.

Notice what these have in common: none of them produces a word that does not exist. They all produce real English words in an order or a form that a native speaker would not choose. That is why proofreading tools miss them and why you have to learn the patterns.

Tip: Record yourself speaking English for two minutes, then transcribe it by hand. The missing to be and the unmarked past tense will jump off the page in a way they never do while you are speaking.

9Kinship pronouns, and why you asked your manager her age

Vietnamese chooses a pronoun based on relative age and relationship. You cannot say I and you until you know how old the other person is. English has one I and one you for everyone, and the habits that Vietnamese requires become mistakes in English.

Anh, chi, em, co, chu, bac, ong and ba are all used as everyday pronouns for people who are not related to you. A slightly older colleague is anh. A slightly younger one is em. This is normal, warm, and correct in Vietnamese.

Translated literally, it produces My brother in the sales team said, or This is my sister, she works with me, about a colleague. English speakers hear a family relationship and get confused. Use colleague, coworker, my manager, a friend, or simply his name.

The age question

Because the pronoun depends on age, asking someone's age early is not rude in Vietnamese; it is necessary. In Canada, the United Kingdom, the United States and Australia, asking an adult their age at a first meeting, especially a woman and especially a manager, is a real social error. You never need the answer in English, because English has no pronoun that depends on it. Simply do not ask.

Names and titles

Vietnamese uses given names with a title: Mr Nam rather than Mr Nguyen, because the family name comes first and is shared very widely. English uses the family name: Mr Miller, not Mr Tom. If you introduce yourself as Nguyen Van Nam to an English speaker, expect them to call you Nguyen, so tell them which name you want used. Most Vietnamese people in English-speaking workplaces say, my name is Nam.

None of these is a vocabulary error. They are all correct English sentences that create a wrong impression, which makes them more costly than a mispronounced word and far harder to notice.

Tip: In English, default to the person's name plus their role. It is the safest option in every English-speaking country, and it never sounds cold in a professional setting the way it might in Vietnamese.

10Greetings and small talk that do not survive translation

These are the phrases that make a fluent speaker sound odd, because they are translated perfectly and used wrongly.

Di dau day, where are you going, is a greeting in Vietnamese and an interrogation in English; say hi, or how are you
An com chua, have you eaten yet, is a warm Vietnamese greeting and in English is either an invitation or a strange question; say how are you, or how is your day going
Vietnamese answers a negative question by agreeing with the proposition, so You do not like coffee gets yes meaning yes I do not; in English yes always means you do like it, so answer no, I do not
Thank you and sorry are used far less inside a Vietnamese family than an English one; in English, thank a family member out loud, because silence reads as ungrateful, not as closeness
Vietnamese refuses indirectly to preserve face, so a soft maybe reads to an English speaker as a real maybe; if you mean no, say I am afraid I cannot
Compliments are deflected in Vietnamese, khong co gi dau, but in English deflecting a compliment twice reads as awkward; say thank you and stop
Vietnamese uses a, da and nhe to soften; English softens with modal verbs, so Could you possibly, I was wondering if, and Would you mind carry the same weight

The blunt-request problem is worth its own note. Vietnamese requests are often direct because politeness lives in the particles and the pronoun, both of which vanish in English. Send me the file becomes an order in English even when it was gentle in Vietnamese. Could you send me the file when you get a chance is the same sentence with the politeness put back where English keeps it.

This is the whole pattern in one sentence: every language carries politeness somewhere, and when you translate word for word, the politeness is the part that gets lost, because it was never in the words.

The cost is real and invisible. Nobody tells you that your email sounded rude. They just answer more slowly, or not at all.

Tip: Collect five polite English request formulas and use them until they are automatic. Could you, would you mind, I was wondering if, when you get a chance, and if it is not too much trouble will cover almost every situation you need.

11Twelve sentences to correct

Each of these contains one error from this guide. Try each before reading the correction.

I bought a new chemise for the interview. Correction: I bought a new shirt for the interview. So mi is a shirt; chemise is an undergarment.
She very beautiful and very kind. Correction: She is very beautiful and very kind. Vietnamese needs no verb before an adjective; English does.
I remember my family very much. Correction: I miss my family very much. Nho covers both, and this is the miss half.
Please open the light, the room is dark. Correction: Please turn on the light, the room is dark.
Yesterday I go to the office at eight. Correction: Yesterday I went to the office at eight. The time word does not do the work in English.
My brother in the finance team will send the report. Correction: My colleague in the finance team will send the report, unless he really is your brother.
The total is 12,5 million dong. Correction: The total is 12.5 million dong, in English punctuation.
I have learned English for three years. Correction: I have been studying English for three years. Study is the activity, learn is the result.
He must drink this medicine two times a day. Correction: He should take this medicine twice a day.
I want to discuss about the new schedule. Correction: I want to discuss the new schedule. Discuss takes no about.
I pity you, you work so hard. Correction: I really feel for you, you work so hard. Thuong is not pity in English.
I recommend you to arrive early. Correction: I recommend arriving early, or I recommend that you arrive early.

Tip: Twelve is more than you can absorb at once. Pick the three you actually made this month and drill only those.

12How to find your own false friends

A list somebody else wrote will never match your errors exactly. This is the process for finding the ones that are actually costing you.

Do this with real English you produced: an email you sent, a message to a colleague, an exam answer, a transcript of yourself speaking. Not exercises, because exercises make you careful and false friends only appear when you are not.

The test

For every noun and verb you were not completely sure of, search the English word alone and read three real sentences using it. If none of those sentences could contain your sentence, you have found a false friend. This works because false friends fail on collocation before they fail on meaning: the definition looks right and the company the word keeps is wrong.

Take a piece of English you wrote without checking, at least two hundred words
Underline every word that came to you from Vietnamese rather than from English
For each one, search the English word and read three real examples from native sources
Mark it wrong if your sentence does not fit the pattern of those three
Write the correct version as a full sentence, never as a single word
Check separately for the two invisible ones: a missing to be before an adjective, and a past-tense verb left unmarked
Keep the list in one file and reread it before you write anything that matters

Expect to find between five and fifteen in your first two hundred words. That is normal, and the number falls quickly, because false friends are a finite list rather than a general weakness.

Tip: The fastest version of this is to read English aloud while listening to a native speaker say the same thing, which is what subtitled podcasts give you. You hear the collocation and the pronunciation together, and collocation errors surface immediately because the pairing sounds wrong before you can explain why.

Frequently asked questions

Are Vietnamese-English false friends really different from Spanish or French ones?

Yes, and in a way that matters. Spanish and English share Latin roots directly, so Spanish false friends are mostly single words with drifted meanings. Vietnamese has three separate sources: words that arrived through French colonial administration, English words that Vietnamese reshaped in the last thirty years, and native Vietnamese words whose range no English word matches. Each needs a different fix, so a general false-friend list will only help you with one third of the problem.

Which errors should I fix first if I am preparing for an English exam?

Two, in this order. First, the missing to be before adjectives, because it appears in almost every spoken answer and it is the strongest marker of a Vietnamese speaker's English. Second, unmarked past tense, because an examiner scoring grammatical range will hear it in every narrative answer. Vocabulary false friends cost you far fewer marks than either, because an examiner can usually work out what you meant.

Is hot girl really a problem? Everyone in Vietnam uses it.

In Vietnamese it is a neutral noun that appears in newspaper headlines. In English it is crude and would be inappropriate in a workplace, an exam, or a job application. This is the clearest case in the whole guide of a word that is completely normal in one language and damaging in the other. Use influencer or content creator.

How do I know whether to use study or learn?

You study a subject and you learn a fact or a skill. Study is the activity and it can fail; learn is the result and it cannot. So I studied for three hours describes what you did, and I learned three new phrases describes what you got. If you can put a length of time on it, the verb is almost always study.

Why does my English sound rude when I translate directly from Vietnamese?

Because Vietnamese carries politeness in the pronoun and in final particles like a and nhe, and English carries it in modal verbs and hedges. When you translate the words, the politeness is exactly the part with no English word to land in, so it disappears. The fix is not to be more polite in feeling but to add the English carriers: could you, would you mind, when you get a chance, I was wondering if.

How long does it take to stop making these mistakes?

The one-to-one vocabulary false friends go quickly, usually within weeks of noticing them, because there are only a few dozen and each is a single decision. Collocations take months, because they are motor habits and need repetition rather than understanding. The missing to be is the fastest to understand and the slowest to remove from speech, so attack it deliberately rather than waiting for it to fade.