The difference between ใ and ไ – Don’t know if it’s been discussed here yet, but this is a question learners always ask. Why are there two /ai/ vowel frames? Answer – The roly ใ ไม้ม้วน was originally pronounced more like /aɯ/ (อะ+อึ), while the floppy ไ ไม้มลาย was originally pronounced /ai/ or in some places /ei/. The /e/ moved back leaving it as /ai/ and the /ɯ/ อึ moved forward turning into an /i/ leaving also /ai/. If you go to Chiangmai you can still hear words like ให้ being pronounced as หื้อ or Luang Prabang – ใ /aɯ/, so the sentence ใส่ข้างใน would be pronounced ‘saɯ kʰa:ŋ naɯ’.
Jan Badertscher had the following to add:
If I woud have to guess I’d say it came from a sanskrit difference, lost in Thai. Thanks to you Stu I now know that it was in deed a vowel frame difference.
To which Stuart Jay Raj replied:
Jan…no. The ใ doesn’t occur in Sanskrit words.It’s a Tai sound… that’s why there are only 20 words that use it.
Also the following youtube video was posted by Jørgen Nilsen
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