Modal vs Non-Modal vs Auxiliary modal vs Conjugated Verb

  1. How are these kinds of verb related to each other?
  2. Specially Non-Modals and Conjugated Verb.
  3. Is the "Auxiliary modal" just another name for "Auxiliary verb"?

I will give you the traditional definitions, although some other people use slightly different definitions. But I think these are what you are looking for.

A modal verb is one that adds information about the probability or desirability of the infinitive that comes with it, like can, will, must, etc.

An auxiliary verb is one that "supports" another verb, which must be an infinitive or a participle; that is, an auxiliary cannot normally be the only verb in a (main) clause. All modal verbs are normally auxiliary verbs in English. So must is modal auxiliary, while be is non-modal auxiliary in I am walking . Note that be, do, and have are only auxiliaries in some sentences—not if they do not support an infinitive or participle. So, in there were two men, the verb be is not auxiliary at all.

A conjugated verb is strictly speaking a verb that changes form as the subject changes from singular to plural: the different forms have different endings. So he walks / they walk.

There is one problem in English: the endings of the modal verbs, while present in older English and other languages, have been dropped or elided for the present tense in modern English. All modal verbs are traditionally still considered finite verbs, even though they have no visible endings any more in the present tense. The reason is that all verbs that aren't infinitives, gerunds, or participles function the same way and should be in the same category, and they must be finite verbs; and modals function just like conjugated verbs. Most of them still get a different form in the past tense, though (could, would, etc.) Another criterion by which to recognise a finite verb is that it comes before the subject in direct questions and negations: he will go there => will he go there? Non-modal auxiliaries can be finite verbs, participles, or infinitives, but modal auxiliaries can only be finite verbs.

One other category is copulae. Verbs that connect a subject with a subject complement are copular, like the verbs be, become, remain, etc. So the verb is a copula in she was angry, they are wolves, he remained a teacher. So the verb be can be auxiliary, copula, or "content word", although opinions differ on when it is which. And some scholars do not recognise all of these distinctions.

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    I would not say that a copular verb was an auxiliary verb, but otherwise correct in so far as it is possible to summarise a complex matter of grammar in a few lines. Nov 16 '13 at 21:07
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    @long: Thanks! I'm afraid I don't see the mistake, though...? Nov 16 '13 at 21:57
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    @GATA: I agree with Barrie. Need can be a modal auxiliary or a regular verb, depending on the construction: you need not stay (auxiliary modal; usually with negations); you need to call her (regular verb). Note that non-auxiliary verbs that are about probability or desirability are usually not called "modals". Nov 16 '13 at 22:02
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    Not all grammars recognise need as a semi-modal verb, but one that does suggests that it is found mainly in British English, and that in general it occurs only in negatives. Nov 17 '13 at 7:43

There are two kinds of auxiliary verb, primary and modal. The primary auxiliary verbs are be, have and do. The modal auxiliary verbs are can, may, might, could, would, will, shall, must and should. (Had) better, have to, (have) got to, ought to, be supposed to, be going to and used to are semi-modal verbs.

All verbs except the modal verbs, and some of the semi-modals, conjugate. That means they change their form to indicate tense and person. Walk, for example, becomes walks after he and she in the present tense, and walked in the past tense. Be becomes is after he, she and it in the present tense and, in the past tense, was after I and he, she and it and were after you, we and they.

  • Where 'is to/are to' that is " be+ to" be grouped? Sep 20 '16 at 15:08

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