Consonants
The 27 consonants of the Lao alphabet are divided into three tone classes—high (ສູງ ), middle (ກາງ ), low (ຕ່ຳ tām)—which determine the tonal pronunciation of the word in conjunction with the four tone marks and distinctions between short and long vowels, but aside from tone, there are 21 distinct consonant sounds that occur in the Lao language. Each letter has an acrophonical name that either begins with or features the word prominently and is used to teach the letter and serves to distinguish them from other, homophonous consonants. The letter ອ is a special null consonant used as an anchor for vowels, which cannot stand alone, as well as serves as a vowel in its own right.
Read more about this topic: Lao Alphabet