Thai has short and long vowels. Vowel length is part of the word, and changing it can change the meaning. The actual duration varies with the speaker, speaking rate, and sentence.
Practice technique: Give a short vowel one beat and a long vowel two beats: คุณ (short), คูณ (long). Real Thai does not use an exact fixed 1:2 timing rule—the taps simply help you feel the contrast.
Start here: the consonants and mid tone stay the same. Listen for the vowel length.
short -u-
คุณ
you; polite title
long -uu-
คูณ
multiply
Another clear comparison: the consonants and low tone stay the same.
short -a-
ปัก
stick in; plant; embroider
long -aa-
ปาก
mouth
Later noticing: tone also changes from low to mid, and the short word has a glottal closure. These differ in more than length.
short -a-
กะ
estimate; roughly judge (as in กะเวลา, estimate the time)
long -aa-
กา
kettle / teapot
Later noticing: tone also changes from low to mid, and the short word has a glottal closure. Listen specifically to the vowel.
short -u-
ดุ
fierce / strict (as in หมาดุ, a fierce dog)
long -uu-
ดู
to look / to watch
How the pairs are written
These are the basic vowel patterns. In a closed syllable, the short vowel may be written differently—for example, เ◌ะ becomes เ◌็ before a final consonant.
◌ะ ↔ ◌า
short a ↔ long aa
◌ิ ↔ ◌ี
short i ↔ long ii
◌ุ ↔ ◌ู
short u ↔ long uu
เ◌ะ ↔ เ◌
short e ↔ long ee
Key insight
Listen for whether the vowel is brief or held. Other parts of the word may also differ, so the clearest practice pairs keep the consonants and tone the same.
Try what you learned
Hear a short and a long vowel
Try คุณ and คูณ from the lesson. Both have a mid tone and the same consonants. Listen, replay, then choose short or long. This is supported practice, not a test of new speech.
Use the lesson above whenever you need help. This is practice, not a level test.