I have been working through the AUA books entitled Reading and Writing. The Thai writing system has 44 consonants, which are divided into three classes, arbitrarily named high, mid, and low. The consonant classes are used to determine tones. One of the challenges Thai students face is to learn which consonants belong to which class. During the Thai class I took in graduate school, the writing system was de-emphasized until the second half of the course, at which point there was an intensive memorization effort aimed at the consonant classes and the corresponding rules. I did well with the homework, quizzes, and exams, but I never felt that I had mastered the material.

As usual, I find the AUA approach to be remarkably innovative, well thought-out, and interesting. Rather than jumping right into memorizing classes and tone rules, the AUA book starts by distinguishing sonorant consonants from aspirates and plain stops. Grouping consonants in this way requires no memorization -once the student understands the distinction, it is obvious which group each consonant belongs to. For example, "m" and "n" are sonorants because the larynx vibrates when they are pronounced. Further lessons explain that that sonorants are all low class and plain stops are all mid class, while explaining the tone rules for each class. This makes learning their classes and the corresponding rules very easy. The aspirates then have to be sorted into high and low class. Sorting out the aspirates is also easy, because the initial syllable of the name of each aspirate has either a rising tone (ขอ ไข่) or a mid tone (คอ ควาย). In the former case, the class is high, and in the latter case, the class is low.