From the perspective of linguistic typology, Thai can be considered to be an analytic language. The word order is subject–verb–object, although the subject is often omitted. Thai pronouns are selected according to the gender and relative status of speaker and audience.
Adjectives and adverbs
There is no morphological distinction between adverbs and adjectives. Many words can be used in either function. They follow the word they modify, which may be a noun, verb, or another adjective or adverb.
คนอ้วน (khon uan, [kʰon ʔûan ]) a fat person
คนที่อ้วนเร็ว (khon thi uan reo, [khon tʰîː ʔûan rew]) a person who became fat quickly
Comparatives
Comparatives take the form "A X กว่า B" (kwa,[kwàː]), A is more X than B.
Superlative
The superlative is expressed as "A X ที่สุด" (thi sut, [tʰîːsùt]), A is most X.
เขาอ้วนกว่าฉัน (khao uan kwa chan, [kʰǎw ʔûan kwàː tɕ͡ʰǎn]) S/he is fatter than me.
เขาอ้วนที่สุด (khao uan thi sut, [kʰǎw ʔûan tʰîːsùt])S/he is the fattest (of all).
Because adjectives can be used as complete predicates, many words used to indicate tense in verbs (see Verbs:Tense below) may be used to describe adjectives.
ฉันหิว (chan hiu, [tɕ͡ʰǎn hǐw]) I am hungry.
ฉันจะหิว (chan cha hiu, [tɕ͡ʰǎn tɕ͡àʔ hǐw]) I will be hungry.
ฉันกำลังหิว (chan kamlang hiu, [tɕ͡ʰǎn kamlaŋ hǐw]) I am hungry right now.
ฉันหิวแล้ว (chan hiu laeo, [tɕ͡ʰǎn hǐw lɛ́ːw]) I am already hungry.
Remark: ฉันหิวแล้ว mostly means "I am hungry right now" because normally, แล้ว ([lɛ́ːw]) is a past-tense marker, but แล้ว has many other uses as well. For example, in the sentence
แล้วเธอจะไปไหน ([lɛ́ːw tʰɤː tɕ͡àʔ paj nǎj]): So where are you going?, แล้ว ([lɛ́ːw]) is used as a discourse particle.Verbs
Verbs
Verbs do not inflect. They do not change with person, tense, voice, mood, or number; nor are there any participles.
ฉันตีเขา (chan ti khao, [t͡ɕʰǎn tiː kʰǎw]), I hit him
เขาตีฉัน (khao ti chan, [kʰǎw tiː t͡ɕʰǎn]), He hit me
Passive
The passive voice is indicated by the insertion of ถูก (thuk, [tʰùːk]) before the verb. For example:
เขาถูกตี (khao thuk ti, [kʰǎw tʰùːk tiː]), He is hit. This describes an action that is out of the receiver's control and, thus, conveys suffering.
To convey the opposite sense, a sense of having an opportunity arrive, ได้ (dai, [dâj], can) is used. For example:
เขาจะได้ไปเที่ยวเมืองลาว (khao cha dai pai thiao mueang lao, [kʰǎw t͡ɕaʔ dâj paj tʰîow mɯːaŋ laːw]),He gets to visit Laos.
Remark: dai ([dâj] and [dâːj]), though both spelled ได้, convey two separate meanings. The short vowel dai([dâj]) conveys an opportunity has arisen and is placed before the verb. The long vowel dai ([dâːj]) is placed after the verb and conveys the idea that one has been given permission or one has the ability to do something. Also see the past tense below.
เขาตีได้ (khao ti dai, [kʰǎw tiː dâːj]), He is/was allowed to hit or He is/was able to hit
Negation
Negation is indicated by placing ไม่ (mai,[mâj] not) before the verb.
เขาไม่ตี, (khao mai ti) He is not hitting. or He not hit.
Tense
Tense is conveyed by tense markers before or after the verb.
Present
Present can be indicated by:
กำลัง (kamlang,[kamlaŋ], currently) before the verb for ongoing action (like English -ing form)
อยู่ (yu, [jùː]) after the verb, or by both.
For example:
เขากำลังวิ่ง (khao kamlang wing, [kʰǎw kamlaŋ wîŋ])
เขาวิ่งอยู่ (khao wing yu, [kʰǎw wîŋ jùː])
เขากำลังวิ่งอยู่ (khao kamlang wing yu, [kʰǎw kamlaŋ wîŋ jùː]), He is running.
Future
Future can be indicated by จะ (cha, [t͡ɕaʔ], will) before the verb or by a time expression indicating the future.
For example:
เขาจะวิ่ง (khao cha wing, [kʰǎw t͡ɕaʔ wîŋ]), He will run or He is going to run.
Past
Past can be indicated by ได้ (dai, [dâːj]) before the verb or by a time expression indicating the past. However, แล้ว (laeo, :[lɛ́ːw], already) is often used to indicate the past tense by being placed behind the verb. Or, both ได้ and แล้ว are put together to form the past tense expression.
For example:
เขาได้กิน (khao dai kin, [kʰǎw dâːj kin]), He ate.
เขากินแล้ว (khao kin laeo, [kʰǎw kin lɛ́ːw], He has eaten.
เขาได้กินแล้ว (khao dai kin laeo, [kʰǎw dâːj kin lɛ́ːw]), He's already eaten.
Tense markers are not required.
ฉันกินที่นั่น (chan kin thinan, [t͡ɕʰǎn kin tʰìːnàn]), I eat there.
ฉันกินที่นั่นเมื่อวาน (chan kin thinan mueawan), I ate there yesterday.
ฉันกินที่นั่นพรุ่งนี้ (chan kin thinan phrungni), I'll eat there tomorrow.
Verb constructions
Thai exhibits serial verb constructions, where verbs are strung together. Some word combinations are common and may be considered set phrases.
เขาไปกินข้าว (khao pai kin khao, [kʰǎw paj kin kʰâːw]) He went out to eat, literally He go eat rice
ฉันฟังไม่เข้าใจ (chan fang mai khao chai, [tɕ͡ʰǎn faŋ mâj kʰâw tɕ͡aj]) I don't understand what was said, literally I listen not enter heart
เข้ามา (khao ma, [kʰâw maː]) Come in, literally enter come
ออกไป! (ok pai, [ʔɔ̀ːk paj]) Leave! or Get out!, literally exit go
Nouns
Nouns are uninflected and have no gender; there are no articles.
Nouns are neither singular nor plural. Some specific nouns are reduplicated to form collectives: เด็ก (dek, child) is often repeated as เด็ก ๆ (dek dek) to refer to a group of children. The word พวก (phuak, [pʰûak]) may be used as a prefix of a noun or pronoun as a collective to pluralize or emphasise the following word. (พวกผม, phuak phom, [pʰûak pʰǒm], we, masculine; พวกเรา phuak rao, [pʰûak raw], emphasised we; พวกหมา phuak ma, (the) dogs). Plurals are expressed by adding classifiers, used asmeasure words (ลักษณนาม), in the form of noun-number-classifier (ครูห้าคน, "teacher five person" for "five teachers"). While in English, such classifiers are usually absent ("four chairs") or optional ("two bottles of beer" or "two beers"), a classifier is almost always used in Thai (hence "chair four item" and "beer two bottle").
Pronouns
Subject pronouns are often omitted, with nicknames used where English would use a pronoun. See informal and formal names for more details. Pronouns, when used, are ranked in honorific registers, and may also make a T–V distinction in relation to kinship and social status. Specialised pronouns are used for those with royal and noble titles, and for clergy. The following are appropriate for conversational use:
Word RTGS IPA Meaning
ผม phom[pʰǒm] I/me (masculine; formal)
ดิฉัน dichan[dìʔt͡ɕʰán]) I/me (feminine; formal)
ฉัน chan[t͡ɕʰǎn] I/me (mainly used by women; informal) Commonly pronounced as [t͡ɕʰán]
เรา rao[raw] we/us, I/me (casual), you (sometimes used but only when older person speaks to younger person)
คุณ khun[kʰun] you (polite) ท่าน than[tʰân] you (polite to a person of high status)
เธอ thoe[tʰɤː] you (informal), she/her (informal)
พี่ phi[pʰîː] older brother, sister (also used for older acquaintances)
น้อง nong[nɔːŋ] younger brother, sister (also used for younger acquaintances)
เขา khao[kʰǎw] he/him, she/her
มัน man[man] it, he/she (sometimes casual or offensive if used to refer to a person)
The reflexive pronoun is ตัวเอง (tua eng), which can mean any of: myself, yourself, ourselves, himself, herself, themselves. This can be mixed with another pronoun to create an intensive pronoun, such as ตัวผมเอง (tua phom eng, lit: I myself) or ตัวคุณเอง (tua khun eng, lit: you yourself). Thai also does not have a separate possessive pronoun. Instead, possession is indicated by the particle ของ (khong). For example, "my mother" is แม่ของผม (mae khong phom, lit: mother of I). This particle is often implicit, so the phrase is shortened to แม่ผม (mae phom). Plural pronouns can be easily constructed by adding the word พวก (puak) in front of a singular pronoun as in พวกเขา (puak khao) meaning they or พวกเธอ (puak thoe) meaning the plural sense of you. The only exception to this is เรา (rao), which can be used as singular (informal) or plural, but can also be used in the form of พวกเรา (puak rao), which is only plural.
Thai has many more pronouns than those listed above. Their usage is full of nuances.
For example:
ผม
เรา
ฉัน
ดิฉัน
หนู
กู
ข้า
กระผม
ข้าพเจ้า
กระหม่อม
อาตมา
กัน
ข้าน้อย
ข้าพระพุทธเจ้า
อั๊ว
เขา
all translate to "I", but each expresses a different gender, age, politeness, status, or relationship between speaker and listener.
เรา (rao) can be first person (I), second person (you), or both (we), depending on the context. When speaking to someone older, หนู (nu) is a feminine first person (I). However, when speaking to someone younger, the same word หนู is a neuter second person (you).The second person pronoun เธอ (thoe) (lit: you) is semi-feminine. It is used only when the speaker or the listener (or both) are female. Males usually don't address each other by this pronoun. Both คุณ (khun) and เธอ (thoe) are polite neuter second person pronouns. However, คุณเธอ (khun thoe) is a feminine derogative third person. Instead of a second person pronoun such as "คุณ" (you), it is much more common for unrelated strangers to call each other "พี่ น้อง ลุง ป้า น้า อา ตา ยาย" (brother/sister/aunt/uncle/granny). To express deference, the second person pronoun is sometimes replaced by a profession, similar to how, in English, presiding judges are always addressed as "your honor" rather than "you". In Thai, students always address their teachers by "ครู คุณครู อาจารย์" (each means teacher) rather than คุณ (you). Teachers, monks, and doctors are almost always addressed this way.
Particles
The particles are often untranslatable words added to the end of a sentence to indicate respect, a request, encouragement or other moods (similar to the use of intonation in English), as well as varying the level of formality. They are not used in elegant (written) Thai. The most common particles indicating respect are ครับ (khrap, [kʰráp], with a high tone) when the speaker is male, and ค่ะ (kha, [kʰâ], with a falling tone) when the speaker is female; these can also be used to indicate an affirmative, though the ค่ะ (falling tone) is changed to a คะ (high tone).
Other common particles are:
Word RTGS IPA Meaning
จ๊ะ cha/ja[t͡ɕáʔ] indicating a request
จ้ะ, จ้า or จ๋า cha/ja[t͡ɕâː] indicating emphasis
ละ or ล่ะ la[láʔ] indicating emphasis
สิ si[sìʔ] indicating emphasis or an imperative
นะ na[náʔ] softening; indicating a request