Compound verbs, a highly visible feature of Hindi–Urdu grammar, consist of a verbal stem plus a light verb. The light verb (also called "subsidiary", "explicator verb", and "vector") loses its own independent meaning and instead "lends a certain shade of meaning" to the main or stem verb, which "comprises the lexical core of the compound". While almost any verb can act as a main verb, there is a limited set of productive light verbs. Shown below are prominent such light verbs, with their independent meaning first outlined, followed by their semantic contribution as auxiliaries. Finally, having to do with the "manner" of an occurrence, compounds verbs are mostly used with completed actions and imperatives, and much less with negatives, conjunctives, and contexts continuous or speculative. This is because non-occurrences cannot be described to have occurred in a particular manner. The auxiliaries when combined with the main verb provides an aspectual sense to the main verb it modifies. Light verbs such as "jānā "to go", ānā "to come", "'cuknā when combined with the main verb give the formed compound verb a perfective aspect, while retaining the original meaning of the main verb.