I was looking through some words and came across ไม้. I would have expected it to be pronounced with a short vowel, mai. However, everywhere I check lists the pronunciation as that of a long vowel, maai. Why is this a long vowel ? Is it irregular ? Thank you for any help.

น้ำ

náam

Water

Is another that you would expect a short vowel, but it is long.

They are both high tone, so I don't know if that has anything to do with it, but other high tone words are pronounced short.

I dont think that there are any rules, probably just irregular, but maybe somebody knows for sure?

Edited May 17, 200917 yr by loong

Thank you very much, the reference page on irregulars at thai-language.com is great.

It's pronounced long when it's stressed, but short when it's unstressed.

The final syllable of a compound or phrase is typically stressed, and thus long:

Pronounced long: ต้นไม้, ดอกไม้, กิ่งไม้, etc.

When ไม้ is the first syllable in a compound, it will usually be unstressed, and thus shortened:

Pronounced short: ไม้มลาย, ไม้เท้า, ไม้ล้มลุก, ไม้เอก, etc.