How to say “Yes” in Thai
ใช่
châi
“yes / that's right”
“Yes” in Thai is ใช่, written châi in the Latin alphabet.
Tone
ใช่ carries a falling tone — starts high, drops hard. Thai uses tone to tell words apart, so the pitch is part of the word, not an accent you can drop.
The shortest way in is an English intonation you already use. Say “NO!” out loud — snapped at a dog going for the food on the table — then say ใช่ with that same shape.