i ask is why mid consonant do not sound 1,but you just tell me have two kind of tone。i do not know your means.

I told about "Tone Forms in writting" ka not concern or not about Tone Sounds so when writting in Thai we have 2 type that I said above but when speak it have 5 tone normally ka :)

but i do not know why not each thai word do not have 5 tone? you tell me have 2 kind of tone,one thai tone have tone mark,one kind is not tone mark.why have not tone mark?

Hi guimengyuan,I've known information for your question I've been Chiang Mai and learnt to Teach Thai for foreigner,ok just opend your mind and your question will be clear. Because in Thai writting Rule we have 2 type of Mark tone for writting there are 1.Have mark tone form(you can see 4 forms ไม้เอก ไม้โท ไม้ตรี ไม้จัตวา) 2.Have "NO" mark tone form so your question word is in 2 type so NO have to put Mark tone form but when you pronounce you will hear MArk tone sound in each word.

i can not know your means.