Not (formal) in Thai

The formal “not” in Thai is มิmí, mostly in มิได้mí-dâi and มิใช่mí-châi; in speech it's ไม่mâi.

มิได้ mí-dâi

not, did not (formal) adverb written

mí high
dâi falling

High: start high and go a little higher, a bit tense; don’t let it fall.
Falling: start high and drop clearly, like a firm “No!”

มิใช่ mí-châi

is not, isn't (formal) adverb written

mí high
châi falling

High: start high and go a little higher, a bit tense; don’t let it fall.
Falling: start high and drop clearly, like a firm “No!”

มิ mí

not (formal, written) adverb

mí high

High: start high and go a little higher, a bit tense; don’t let it fall.

How to use it

มิmí is the old, formal "not". You'll meet it mostly as มิได้mí-dâi, "did not, does not", and มิใช่mí-châi, "is not", in the news, laws and literature, and in มิฉะนั้นmí-chà-nán, "otherwise".

In speech Thais say ไม่mâi, ไม่ได้mâi dâi (didn't) and ไม่ใช่mâi châi (isn't).

Other spellings you'll see

There's no single official way to write Thai in English letters. We mark the tone of every syllable; online you'll also find:

mee dai
mee chai

More formal words in Thai

All formal words

การ gaan Kaan (prefix)
-ing, -tion: turns a verb into a noun (the act of …)
ความ kwaam Kwaam (prefix)
-ness (turns a verb or adjective into a noun)
ผู้ pûu Phu (prefix)
person (who …): makes words for people, like -er
นัก nák Nak (prefix)
-er, -ist: someone who does it (as a job or a passion)
ซึ่ง sûeng Who, which (formal)
which, who (adds information; formal, written)
เมื่อ mûea When (formal)
when, once (formal)

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Written by the Learn Thai For Free team
Audio: AI voices, quality-checked for tones