Khan Academy : Verbs!
irregular verb
A verb in which the past tense is not formed by adding the usual -ed ending.
linking verb
A verb that does not show action but connects the subject with a word in the predicate.
auxiliary(helping) verb
Helping verbs are verbs that help the main verb in a sentence by extending its meaning.
verb
An action word.
modal verbs
An auxiliary verb that expresses necessity or possibility.
Progressive perfect verb aspect
Any verb (in the past, present or future) in the perfect progressive tense.
progressive verb aspect
Progressive aspects are used to describe actions that happen over an extended period of time.
perfect verb aspect
The perfect aspect (or complete aspect as it's sometimes called) is the aspect of a verb which expresses a completed action.
simple verb aspect
The simple aspect includes all verbs in the simple tense (past, present, or future).
verb agreement
The subject and verb must agree in number: both must be singular, or both must be plural.
verb tense
Verb that tells the time of the action or being.