Three of the most common verbs in the English language are the auxiliary verbs "be," "have" and "do," because they are used so often in conjunction with other verbs. Other common English verbs represent frequent actions, such as "say," "go" and "make."
Many verb phrases in English use more than one verb; typically, such a verb phrase contains a small auxiliary verb and a main verb. For example, the verb phrase "is sleeping" contains the auxiliary verb "is" (a conjugation of "be") and the main verb "sleeping." There are hundreds of unique main verbs but only a handful of auxiliary verbs, so auxiliary verbs tend to be among the most common. In fact, the auxiliary verb "be" is not only the most commonly used verb, but the second most commonly used of all English words (behind only "the").
Because language is used to describe thoughts and actions, the most commonly used English verbs aside from auxiliary verbs are those that represent common thoughts and actions. The verbs "know," "think" and "understand" are used often to describe thoughts and emotions, while action verbs are used as often as the corresponding actions are performed. The verbs "say," "go" and "see," for example, are used whenever one describes the common actions of saying something, going somewhere or seeing someone.