The four answers to English “is”

The sentence that trips up nearly every learner is the simplest one on the list. You want to say "she is beautiful". You know that สวย (sǔay) means "beautiful" and that เป็น (bpen) is the word for "is", so you produce เขาเป็นสวย, and the Thai person in front of you gives you a small confused pause. The sentence is เขาสวย (khǎo sǔay). Two words. There is no verb "to be" in it, and there cannot be one. สวย is not an adjective in the English sense at all. It is a verb, and it already means "is beautiful" by itself. Putting เป็น in front of it produces something close to "she is is beautiful". (One note on the transliteration: written tone rules make เขา rising, khǎo, and that is how it is spelled throughout this lesson, but as a pronoun it is normally said with a high tone, kháo.) Thai has a large class of these words, usually called stative verbs, and they behave like verbs in every way. ดี (dii) is "is good", เก่ง (gèng) is "is skilled", แพง (phaeng) is "is expensive", ถูก (thùuk) is "is cheap", ร้อน (ráwn) is "is hot", หนาว (nǎao) is "is cold", หิว (hǐu) is "is hungry", เหนื่อย (nèuay) is "is tired", ง่วง (ngûuang) is "is sleepy", ใหญ่ (yài) is "is big", เล็ก (lék) is "is small". Because they are verbs, you negate them directly with ไม่ (mâi), so ไม่แพง (mâi phaeng) is "is not expensive". You question them directly with ไหม (mǎi), so แพงไหม (phaeng mǎi) is "is it expensive?". You strengthen them with มาก (mâak) placed after, so แพงมาก is "is very expensive". And when the same word sits after a noun instead of after a subject, it simply becomes a modifier: คนสวย (khon sǔay) is "a beautiful person", while เขาสวย is "she is beautiful". Nothing changes except what comes in front of it. The same silence happens in several other places where English insists on "is". Prices: อันนี้ห้าสิบบาท (an-níi hâa-sìp bàat), "this one is fifty baht". Age: ผมอายุสี่สิบปี (phǒm aa-yú sìi-sìp bpii), "I am forty". Clock time: ตอนนี้บ่ายสองโมง (dtawn-níi bàai sǎwng moong), "it is two in the afternoon". Weather and general conditions: วันนี้ร้อนมาก (wan-níi ráwn mâak), "it is very hot today". Two more sentences lose their "is" the same way, and they are the first two you say to a stranger. Names take ชื่อ (chêu), which is a verb in its own right meaning "to be named": ผมชื่อจอห์นครับ (phǒm chêu jawn khráp), "my name is John", and คุณชื่ออะไรครับ (khun chêu à-rai khráp), "what is your name?". ชื่อของผมคือ is English wearing Thai words and nobody says it. Origin takes มาจาก (maa jàak), "come from": ผมมาจากฝรั่งเศส (phǒm maa jàak fà-ràng-sèet), "I am from France". ผมเป็นคนฝรั่งเศส (phǒm bpen khon fà-ràng-sèet) is equally normal, and it is a plain เป็น plus noun, so both routes are open here. If you find yourself hunting for a to-be word in any of those, the answer is that Thai does not have one there. So when is เป็น actually correct? The condition is worth memorising as a shape rather than as a rule: subject + เป็น + NOUN. It places the subject inside a category. ผมเป็นครู (phǒm bpen khruu), "I am a teacher". เขาเป็นคนไทย (khǎo bpen khon thai), "he is Thai". เธอเป็นแฟนผม (thoe bpen faen phǒm), "she is my girlfriend". เขาเป็นเจ้าของร้าน (khǎo bpen jâo-khǎwng ráan), "he owns the shop". Jobs, nationalities, relationships, roles and memberships all work this way. Before you say เป็น, look at the word that is about to follow it. If it names a thing or a kind of person, เป็น is right. If it names a quality, you need nothing. เป็น then takes on several jobs that English gives no hint of, and they are common enough that you will meet all of them in your first month here. It is the verb for having an illness: เป็นหวัด (bpen wàt) "have a cold", เป็นไข้ (bpen khâi) "have a fever", เป็นแผล (bpen phlǎe) "have a wound". That is why เป็นอะไร (bpen à-rai) means "what is wrong with you", not "what are you", and you will meet it at any clinic, usually with มา added: เป็นอะไรมาครับ (bpen à-rai maa khráp), "what has brought you in". The same เป็น asks about the state of anything at all, not only of a sick person: เป็นยังไงบ้างครับ (bpen yang-ngai bâang khráp), "how are things, how is it going", to a neighbour or a colleague, and งานเป็นยังไงบ้าง (ngaan bpen yang-ngai bâang), "how is work?". Once you hear เป็นอะไร and เป็นยังไง as one family, both asking what state something is in, the illness use stops feeling random: a cold is a state you are in, not a thing you own. เป็น also carries the sense of becoming, as in ลูกชายผมอยากเป็นหมอ (lûuk-chaai phǒm yàak bpen mǎw), and กลายเป็น (glaai bpen) is "turn into". It means "as" in the sense of a capacity: เขาทำงานเป็นล่าม (khǎo tham-ngaan bpen lâam), "he works as an interpreter". It means "in" with languages and formats: เขียนเป็นภาษาไทย (khǐian bpen phaa-sǎa-thai), "write it in Thai". And placed after a verb rather than before a noun, it means "know how to": ว่ายน้ำเป็น (wâai-náam bpen) "can swim", ขับรถเป็น (khàp rót bpen) "can drive", พูดไทยเป็น (phûut thai bpen) "can speak Thai". That last one is a genuinely separate เป็น, and it is the one negated as พูดไม่เป็น (phûut mâi bpen), "cannot speak it". เป็น here is narrower than English "can". It means the skill was learned and is now yours. ได้ (dâi) means you are able to do it in the circumstances, and it is by far the commoner word: ขับรถได้ (khàp rót dâi). After two beers you still ขับรถเป็น but you ขับรถไม่ได้, and that gap is the whole difference. What people will actually ask you is พูดไทยได้ไหมครับ (phûut thai dâi mǎi khráp), and the useful answer is ได้นิดหน่อยครับ (dâi nít-nàwy khráp), "a little". Negating เป็น catches people out, because in an identity sentence you do not negate เป็น at all. The negative of "I am a teacher" is ผมไม่ใช่ครู (phǒm mâi châi khruu), built on ไม่ใช่ (mâi châi), which is the standing negative for any identity statement and also serves as the negative of คือ. ไม่เป็นครู is not what a Thai speaker reaches for to say that. There is a second option, ไม่ได้เป็น (mâi dâi bpen), which denies a role someone has assumed you hold: ผมไม่ได้เป็นหมอครับ (phǒm mâi dâi bpen mǎw khráp), "I am not actually a doctor". ไม่ does sit directly in front of เป็น in the other jobs เป็น does, and those are common: ผมไม่เป็นอะไรครับ (phǒm mâi bpen à-rai khráp), "I am fine, nothing is wrong with me", which is what you say after a fall or a near miss; ว่ายน้ำไม่เป็น (wâai-náam mâi bpen), "I cannot swim"; and the frozen ไม่เป็นไร (mâi bpen rai), "never mind, it is fine", which you learn whole and do not take apart. So the ban is narrower than it looks. It is not "never put ไม่ before เป็น". It is "never negate a job, a nationality or a relationship with ไม่เป็น, use ไม่ใช่". There is a fourth small word in this system, and you meet it every time somebody checks something with you. ใช่ (châi) is the positive half of ไม่ใช่. You do not build statements with it, because ผมใช่ครู is not Thai, but you ask and answer with it constantly. A เป็น sentence is not questioned by adding ไหม the way แพงไหม is; คุณเป็นครูไหม sounds wrong. You tag it instead: คุณเป็นครูใช่ไหมครับ (khun bpen khruu châi mǎi khráp), "you are a teacher, right?", when you already half expect yes, or คุณเป็นคนอังกฤษหรือเปล่าครับ (khun bpen khon ang-grìt rěu-bplào khráp), "are you English or not?", which is the neutral open question. The answers are ใช่ครับ (châi khráp) and ไม่ใช่ครับ (mâi châi khráp). That is why ไม่ใช่ feels arbitrary until you see this: it is the negative of a word you hear all day. คือ (kheu) is an equals sign rather than a category label. You use it when both halves of the sentence point at the same specific thing and could be swapped without changing the meaning. ผู้จัดการคือคุณสมชาย (phûu-jàt-gaan kheu khun sǒm-chaai), "the manager is Khun Somchai". นี่คือหนังสือเดินทางของผม (nîi kheu nǎng-sěu-doen-thaang khǎwng phǒm), "this is my passport". It is the natural verb for definitions and explanations: ปัญหาคือ (bpan-hǎa kheu) "the problem is", คำตอบคือ (kham-dtàwp kheu) "the answer is". For "X means Y", คือ is possible but usually not the natural word. Use แปลว่า (bplae wâa) when the meaning comes from translating between languages, which is what you say holding up a written word: คำนี้แปลว่าอะไรครับ (kham níi bplae wâa à-rai khráp), "what does this word mean?". Use หมายถึง (mǎai-thěung) or หมายความว่า (mǎai-khwaam-wâa) when you are explaining the sense of something rather than translating it: เกรงใจหมายถึงการไม่อยากรบกวนคนอื่น. Separately, in conversation you will hear คือว่า (kheu-wâa) at the front of a sentence as a hesitation marker, roughly "well, the thing is", and that use has nothing to do with the grammar here. The contrast with เป็น is easiest to feel as a pair. เขาเป็นครู (khǎo bpen khruu) says he belongs to the category of teachers, one of many. เขาคือครูที่ผมเล่าให้ฟัง (khǎo kheu khruu thîi phǒm lâo hâi fang) says he is precisely the teacher I told you about, one identified person. A rough test through English: if the second half would take "a" or "an", use เป็น; if it would take "the" or a name, use คือ. In practice the two overlap, spoken Thai leans heavily on เป็น, and choosing wrongly between them will rarely stop you being understood. คือ sounds more explanatory and turns up more in writing, on signs and in careful speech. อยู่ (yùu) is the "is" of place and presence, and it never competes with the other two. Put it directly in front of a location: ห้องน้ำอยู่ข้างนอก (hâwng-náam yùu khâang-nâwk), "the toilet is outside", or ธนาคารอยู่ตรงข้ามตลาด (thá-naa-khaan yùu dtrong-khâam dtà-làat), "the bank is opposite the market". ที่ (thîi) between the two is optional and slightly more precise: ผมอยู่ที่ทำงาน (phǒm yùu thîi tham-ngaan). The question form is อยู่ไหน (yùu nǎi) or อยู่ที่ไหน. With no place named at all, อยู่ means "is in, is present, is available", which is why คุณหมออยู่ไหมครับ (khun mǎw yùu mǎi khráp) is what you say on the phone to ask whether the doctor is there. It also covers living somewhere over years, not just standing somewhere now: ผมอยู่เชียงใหม่มาห้าปีแล้ว. Written notices use the more formal ตั้งอยู่ (dtâng-yùu) for buildings. One trap sits right beside อยู่. To say that something exists somewhere, Thai uses มี (mii), "there is", not อยู่: แถวนี้มีร้านขายยาไหมครับ (thǎew-níi mii ráan-khǎai-yaa mǎi khráp), "is there a pharmacy around here?". อยู่ is for a thing already known to both speakers: ร้านขายยาอยู่ตรงข้ามโรงพยาบาล (ráan-khǎai-yaa yùu dtrong-khâam roong-phá-yaa-baan), "the pharmacy is opposite the hospital". New thing entering the conversation, มี. Known thing being placed on the map, อยู่. Both อยู่ and มี take a plain ไม่, and you will be on the receiving end of those two negatives far more often than you produce them. คุณหมอไม่อยู่ครับ (khun mǎw mâi yùu khráp), "the doctor is not in", is the standard answer at a clinic counter, and it covers everything from out for lunch to away until Monday, so the sentence to have ready after it is กลับมากี่โมงครับ (glàp maa gìi moong khráp), "what time is he back?". ไม่มี (mâi mii) is the answer to almost any question about stock or availability, usually on its own: ไม่มีครับ. Full sentence: แถวนี้ไม่มีร้านขายยา (thǎew-níi mâi mii ráan-khǎai-yaa), "there is no pharmacy around here". อยู่ has a second life at the end of a sentence, where it marks something still going on. เขากำลังทำงานอยู่ (khǎo gam-lang tham-ngaan yùu) is "he is working right now". You can use กำลัง (gam-lang) alone, อยู่ alone, or both together, with อยู่ leaning towards "still in progress". With ยัง (yang) it gives "still": เขายังโกรธอยู่ (khǎo yang gròot yùu), "he is still angry", and ผมยังเหนื่อยอยู่ (phǒm yang nèuay yùu), "I am still tired". Notice that โกรธ and เหนื่อย are qualities in English and verbs in Thai, which is exactly why they can take อยู่ the way an action verb does. The English "is" in "is working" and in "is still angry" never becomes a Thai word: what carries it is กำลัง and อยู่. Thai does not mark tense, so every sentence here is also a past sentence when the context is past. The one word worth adding now is เคย (khoei), "used to, have ever", which is how a former identity is stated: ผมเคยเป็นครูที่อังกฤษ (phǒm khoei bpen khruu thîi ang-grìt), "I used to be a teacher in England", and ผมเคยอยู่ภูเก็ต (phǒm khoei yùu phuu-gèt), "I used to live in Phuket". Without เคย, ผมเป็นครู will be taken as what you do now. Before any sentence with "is" in it, run five questions in order. Is the next word a quality (beautiful, tired, expensive, hot)? Then use nothing. Is it a noun naming a class (a teacher, a Thai person, a cold)? Then เป็น. Is it a specific thing or person that the subject exactly equals (the manager, this passport, the answer)? Then คือ. Is the sentence about where someone or something is, or about an action still under way? Then อยู่. Is it "there is", something new being introduced rather than located? Then มี. Mixing up เป็น and คือ is a small error that Thai listeners barely register. Putting เป็น in front of an adjective is a large one, and it is the single clearest sign that someone has been translating from English rather than speaking Thai.