741. Verbs are divided into two classes, according to the form of the
present system: I. Root verbs, and verbs in #-ere#, mostly primitive;
II. Verbs in #-āre#, #-ēre#, or #-īre#, mostly denominative.
742. Verbs are sometimes arranged without regard to difference of kind,
in the alphabetical order of the vowel before -s of the second person
singular of the present indicative active, #ā#, #ē#, #i#, #ī#: thus,
#laudās#, #monēs#, #regis#, #audīs#, sometimes called the _first_,
_second_, _third_, and _fourth conjugation_ respectively.