... make up the tense system of English. The six basic verb forms are the base, the present tense, the past tense, the infi nitive, the present participle, and the past participle. The next chapter ... irregular verb run:VERB FORMSBase Present Past Infi nitive Present Pastform tense tense participle participlewalk walk/walks walked to walk walking walkedrun run/runs ran to run running runWe ... helping verbs when we talk about the future, (3) in imperative sentences (commands), and (4) as part of the complement of some verbs.Infi nitivesAll infi nitives are formed by putting to in front...