ใช่ is used as an affirmative response to certain questions. Loosely translated, it means yes, or correct.
mâi-châi
it is not so, no, negative response
châi-mǎi
Isn't that right? Correct?
When ใช่ไหม is added to a statement, it forms a question. It is used when the speaker is seeking confirmation of something. It is very similar to the word หรือ, and in most cases either word can be used.
dâi-mǎi
can you? are you able to?
Note that the first syllable is formed by ก without a vowel. This special spelling has an implied à sound. So you say gà-rú-naa (not grú-naa). gà-rú-naa. กรุณา is one of two different words that are used like the English word please. The other word is โปรด (bròte).
นะ is added to questions to make them sound less abrupt, or nicer.
เปล่า is a particle that means No. It indicates a strong disagreement with the information content of a question. You will often hear the words หรือ เปล่า (rǔu bplào), which is like saying or not? at the end of a statement to form a question. If you strongly disagree, say เปล่า.