Pro-verb

In grammar, a pro-verb is a word or phrase that stands in place of a verb (for example, in order that the verb not need to be repeated). It does for a verb what the more widely known pronoun does for a noun. It, along with pronouns and some other word classes, form the general group of word classes pro-forms. It is a type of anaphora. This term is always hyphenated, to distinguish it from the unrelated term proverb.

Pro-verbs in English

English does not have dedicated pro-verbs; however, a bare infinitive can generally be implied rather than expressed, such that the verbs that take bare infinitives (including most of the auxiliary verbs) can be said to double as pro-verbs. Additionally, "have" and "be" can double as pro-verbs for perfect, progressive, and passive constructions (by eliding the participle). Finally, the dummy auxiliary verb "do" can be used when there is no other auxiliary verb, except if the main verb is "be". The following are some examples of these kinds of pro-verb:

*"Who can tell? —No-one can [tell] ."
*"Why can't he do it? —He can [do it] , he just won't [do it] ."
*"I like pie, as does he [like pie] ."
*"Are you doing it tomorrow? —No, I already have [done it] ."
*"Why did you break the jar? —He made me [break the jar] ."

Note that, when there are multiple auxiliary verbs, some of these may be elided as well. For example, in reply to "Who's been leaving the milk out of the refrigerator?", any of "You've been doing it," "You have been," or "You have" would have the same meaning.

Also note that in some dialects, it is uncommon to completely elide the bare infinitive or participle; rather, a form of the main verb "do" is used. So, the first and second examples above would have been, "No-one can do" and "He can do, he just won't do." In these dialects, "do" is unequivocally a pro-verb (in addition to its other uses).

Since a to-infinitive is just the particle "to" plus a bare infinitive, and a bare infinitive can be elided, the particle "to" doubles as a pro-verb for a to-infinitive:

*"Clean your room! —I don't want to [clean my room] ."
*"He refused to clean his room when I told him to [clean his room] ."

Finally, even in dialects where bare infinitives and participles can be elided, there does exist the pro-verb "do so": "He asked me to leave, so I did so". This pro-verb, unlike the above-described pro-verbs, can be used in any grammatical context; however, in contexts where another pro-verb could be used, it can be overly formal. For example, in "I want to get an 'A', but to do so, I need to get a perfect score on the next test," there is no other pro-verb that could be used; whereas in "I want to get an 'A', but I can't do so," the "do so" could simply be elided, and doing so would make the sentence sound less formal.