IV. Nu- and u-classes (fifth and eighth, su- and tan-classes).

A. The present-stem of the nu-class is made by adding to the root the syllable नु nu, which then in the strong forms receives the accent, and is strengthened to नो nó.

B. The few roots of the u-class (about half-a-dozen) end in न् n, with the exception of the later irregular कृ kṛ (or kar) — for which, see below, 714. The two classes, then, are closely correspondent in form; and they are wholly accordant in inflection.

a. The u of either class-sign is allowed to be dropped before v and m of the 1st du. and 1st pl. endings, except when the root (nu-class) ends in a consonant; and the u before a vowel-ending becomes v or uv, according as it is preceded by one or by two consonants (129 a).