As mentioned in the previous two posts, when considering the spelling of a word in Thai, the consonant class influences the tone of the word. There are three consonant classes: low, mid, and high.

We will continue with the Mid class consonants (MCC) because I believe it is the next easiest of the three.

The mid class consonants are:

ก, จ, ฎ, ฏ, ด, ต, บ, ป, อ

You will need to memorize this list. The MCC are the only consonants that can achieve all five Thai tones. In the following rules I won’t go over every letter, but the rules apply to any of the MCC.

 

1. If a MCC has a live (or no) ending consonant, and no tone mark, the tone is mid.

กา

ดาว

กลาง

ใบ

ใจ

ไป

จาน

ตาม

 

2. If a MCC has a อ้ tone mark, with or without a dead consonant, the tone is falling.

เจ้า

ได้

บ้า

ใต้

จ้า

 

3. If a MCC has a อ่ tone mark, and/or has a dead ending consonant, the tone is low. This is the same for a HCC.

จาก

ปาบ

บาท

จ่า

ไก่

อย่าง

อยู่

อย่า

อยาก

เด็ก

 

Notice the last four examples. The อ is silent, and only exists to modify the tone of the word. Without the อ, each of those four words would have had a falling tone.