But it cannot subcategorize any auxiliary verb. Modal verbs can: *John does have sung. *Mary does be singing. John must have sung. Mary must be singing. For these reasons we do not consider do to be a ...

An auxiliary verb, also called a helping verb, is a verb that is used with another verb (or two other verbs) in a verb phrase. Pronoun Present tense of haber; I (yo) ...

THE following simple-sounding but actually rather complicated grammar question was posted in Jose Carillo’s English Forum recently by Education student Justine Aragones: “How does the use of auxiliary ...