These are verbs that can be meaningful without the support of any other verb. It will suffice to discuss the three major characteristics of lexical verbs: regular and irregular, finite and non-finite, stative and dynamic verbs.
Regular and Irregular
Verbs are either regular or irregular in relation to how the past tense and the past participle are formed. A regular verb forms the past tense and past participle by adding the suffix -ed or -d to the base word, e.g.,
walk walked walked
kill killed killed
refer referred referred
Irregular verbs do not form the past tense and past participle in the regular way but rather vary in forms, e.g.,
go went gone
beat beat beaten
drive drove driven
sing sang sung
split split split
