Modal Verbs Part 2
Words with a similar function to the modal verbsHave to
Have to is used in a similar way to must, as discussed above. Except where Have to is used more with an outside obligation such as You have to wear a seatbelt when driving and must is used more commonly with personal obligations I must go to the dentist.
Ought to and had better
Ought to and had better are used to express an ideal behavior or occurrence or suggested obligation, in a similar way to should. The negations are, respectively, ought not to (or rarely, oughtn't to) and had better not. The "had" in "had better" can be contracted, such as "You'd better shut up." In informal American usage, the had in had better is sometimes omitted.
Used to
Used to is used to express past states that were habitual but which are no longer. For example, "I used to go to college" suggests that the speaker no longer goes to college. Negative constructions exist in expressions such as "She used to not like me", or if the speaker is trying to avoid the split infinitive, "She used not to like me".
In some non-standard dialects, used to can follow did not (or didn't), as in "She didn't use to like me".
Dare and need
Dare and need are not commonly used as auxiliaries nowadays, but formerly they both were. Dare is rare with the exception of "How dare you!". "He dare not do it" is equivalent to "He does not dare to do it", while "It need not happen today" is equivalent to today's "It does not need to happen today" or "It might not happen today." However, in the sentence "I need to lose weight," need is not being used as an auxiliary, as takes the infinitive "to lose" as the head of the verb phrase rather than the bare infinitive "lose" that occurs in a phrase like "I can lose weight".
Do
As an auxiliary, do is essentially a "dummy"; that is, it does not generally affect the meaning. It is used to form questions and negations when no other auxiliary is present: "I do not (don't) want to do it." This particular use of do, known as do-support, is attested from around 1400.
It is also sometimes used for emphasis: "I do understand your concern, but I do not think that will happen." Also, do sometimes acts as a pro-verb: "I enjoy it, I really do [enjoy it], but I am not good at it." (Other auxiliaries do this as well: "I can do it, I really can [do it], it just takes me longer"; but it bears particular note that in the case of do, it is often used as a pro-verb when it would be absent if the verb were present.) Because it does not affect the meaning of its verb, not all grammarians acknowledge do as a modal auxiliary. In a sense, it indicates a lack of modal auxiliary. (Do is also different in that it has a distinct third-person singular form, does, and in that its past tense, did, is used exactly as a past tense, not as a more general remote form).
Double modal
In standard English usage, it is grammatically incorrect to use more than one modal verb consecutively, although modals can be used together with modal-like constructions. Thus, 'might have to' is acceptable, but 'might must' is not, even though 'must' and 'have to' can normally be used interchangeably. A greater variety of double modals appears colloquially in some regional or archaic dialects. In Southern American English, for example, phrases such as might could or ought to should are sometimes used in conversation.[4][5] The double modal may sometimes be redundant, as in "I ought to should do something about it", where ought to and should are synonymous and either one could be removed from the sentence. In other double modals, the two modal verbs convey different meanings, such as "I might could do something about it tomorrow", where might indicates the possibility of doing something and could indicates the ability to do it.
Double modals also occur in the closely related Germanic language Scots.
An example of the double modal used to could can be heard in country singer Bill Carlisle's 1951 song "Too Old to Cut the Mustard":
I used to could jump just like a deer,
But now I need a new landing gear.
I used to could jump a picket fence,
But now I'm lucky if I jump an inch.[6]
These kind of double modal phrases are generally not regarded as correct grammar, although other double modals may be used instead. "I might could do something about it" is more often expressed as "I might be able to do something about it", which is considered more grammatical. Similarly used to could is usually expressed as used to be able to. Double modals can also be avoided by replacing one of the modal verbs with an appropriate adverb, such as using probably could or might possibly in place of might could.
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