Thirteen out of twenty-two consonants, such as "h(a)," are invariant, regardless of the following vowel (that is, they are alphabetic), while only six have a distinct form for each consonant-vowel combination (that is, they are syllabic), and among these, only "d" and "m" occur in three forms for all three vowels: "d" or "da," "dā," "di" or "dī," "du" or "dū." ("k, g" do not occur before "i," and "j, v" do not occur before "u," so these consonants only have two forms each.)