Tense-aspects are formed by combining two kinds of marker: verb inflection, and the use of a system of final auxiliaries. In view of the large number of invariable verbs, oral Tibetan makes extensive use of these auxiliaries. The latter indicate both the tense-aspect and the evidential nature of a given statement, which thereby reveals the source of information from which its authority is derived.

As far as tense-aspect is concerned, Tibetan distinguishes: future, present (similar to the imperfective past), perfective past, and perfect.

Auxiliaries usually go after the main verb, i.e., at the end of the sentence and only rarely within subordinate clauses.