136. In internal combination

In internal combination:

a. The augment a makes with the initial vowel of a root the combinations āi, āu, ār (vṛddhi-vowels: 235), instead of e, o, ar (guṇa-vowels), as required by 127; thus, āita (a + ita), āubhnāt (a + ubhnāt), ārdhnot (a + ṛdhnot).

b. The final o of a stem (1203a) becomes av before the suffix ya (original ia: 1210a).

c. The final vowel of a stem is often dropped when a secondary suffix is added (1203a).

d. For the weakening and loss of radical vowels, and for certain insertions, see below, 249 ff., 257–8.