The Farlex Grammar Book > English Grammar > Parts of Speech > Verbs > Auxiliary Verbs > Semi-Modal Auxiliary Verbs
Semi-Modal Auxiliary Verbs
What are semi-modal auxiliary verbs?
Semi-modal auxiliary verbs, often simply called semi-modal verbs, are verbs that sometimes behave like modal auxiliary verbs. (They are also sometimes known as marginal modal verbs.) Like the “proper” modal verbs, they are used with the base form of verbs (the infinitive without to) to create a unique meaning.
Dare, need, used to, and ought to
Not all sources agree on the complete list of semi-modal verbs, but there are four that are widely considered as the standard set: dare, need, used to, and ought to.
Dare and need are considered semi-modal because they can also function as main verbs, able to take nouns and infinitives as objects and to conjugate for person, tense, and number. Ought to and used to, while unable to be main verbs, are considered semi-modal because they are always followed by infinitives (compared to “true” modals, which can never be followed by infinitives).
As semi-modal verbs, these verbs are used in conjunction with “main” verbs to create a complete verb expression; they do not conjugate for third-person singular subjects; they do not have a simple past tense; and they cannot form infinitives, present participles, or past participles.
We’ll look at each of these verbs individually, examining when and how they function as semi-modal verbs.
When dare is used as a semi-modal verb, it means “to be brave, reckless, or rude enough to do or try something.” Remember, when functioning modally, it does not conjugate for person or tense. For example:
- “If he dare cross me again, I’ll make sure he pays dearly for it.”
As a semi-modal verb, dare more often takes not to form a negative statement (very rarely contracted as daren’t), or is inverted with the subject to form an interrogative sentence. For example:
- “I dare not press the issue any further.”
- “How dare she talk to me like that?”
- “Dare he meddle with the laws of nature?”
- “They daren’t give him a reason to be angry.”
However, with the exception of the now idiomatic phrase “How dare (someone),” the use of dare as a modal verb has become rare in modern English.
As a main verb
Dare can also be used as an intransitive main verb with the same meaning as the modal version. When it functions as a main verb, however, it is able to conjugate for person and tense, and it can be followed by a verb in either its base or infinitive form (the to becomes optional). For example:
- “I can’t believe he dared (to) stand up to the boss.”
- “No one dares (to) question my authority!”
When dare is used as a main verb, it must take the auxiliary verb do to form questions or be made negative. As we saw in the section on primary auxiliary verbs, it is do, rather than the main verb, that conjugates for tense, person, and number in this case. For example:
- “Did they dare (to) go through with it?”
- “He doesn’t dare (to) argue with the principal.”
Dare can also mean “to challenge someone to (do) something that requires courage, boldness, or recklessness,” in which case it must take a noun, pronoun, or infinitive as a direct object. It cannot be used modally with this meaning. For example:
- “I dare you to ask Suzy on a date.”
- “I’ve never been dared to race someone before.”
Need as a semi-modal verb is almost always used in negative sentences to express a lack of obligation or necessity, either taking the adverb not (usually contracted as needn’t) or paired with a negative word or phrase, such as never, no one, nothing, etc. For example:
- “No one need know about this.”
- “He needn’t have called; I told him I would be late.”
- “You needn’t worry about my grades.”
- “Nothing need change simply because my father is no longer here.”
It can also be used to form interrogative sentences by inverting with the subject, as in:
- “Need we be concerned?”
- “Need I go to the market later?”
Like dare, though, the modal use of need has become quite uncommon in modern English, except in very formal speech or writing.
As a main verb
Need is much more common as a main verb. This means it conjugates for person (becoming needs in the third-person singular) or tense (becoming needed), and it uses auxiliary did to form negatives and questions. As a main verb, need can be followed by nouns, noun phrases, pronouns, gerunds, or infinitives. For example:
- “He needs that report by tomorrow.”
- “Does she need to know where the house is?”
- “You have plenty of time, so you don’t need to rush.”
- “He needed a place to stay, so I offered him one.”
When we speak about a past habit, condition, or fact that is no longer the case, we can use the semi-modal used to with the base form of the verb. For example:
- “I used to get up early when I lived in New York.”
- “She used to live in Ireland.”
- “We used to be in a band together.”
- “This watch used to belong to my father.”
Uniquely among the modal and semi-modal verbs, we form the question and negative of used to the same way as for main verbs in the past tense—that is, by using the auxiliary did for the question and did not for the negative.
- “Did you use to live in Manchester?”
- “I didn’t use to like coffee.”
- “She didn’t used* to go to the gym every day.”
(*Technically speaking, we should remove the “-d” from used to when forming questions and negatives, as the auxiliary verb did takes the past tense. Because of to immediately following use, however, the pronunciation stays the same, and many writers include the “-d” regardless. It is common to see it written both ways in modern English.)
As a main verb
A large source of confusion arises around the difference between the semi-modal verb used to and two similarly structured main verbs — be used to and get used to.
Be used to
When we use be used to with a noun, noun phrase, or the gerund of a verb, it means “to be accustomed to something.” For example:
- “I am used to getting up at 7 AM every morning.”
- “She was used to the stress by that point.”
To form the negative of be used to, we add not after the auxiliary verb be, which can be contracted to isn’t, aren’t, wasn’t, or weren’t. To form interrogative sentences, we invert be with the subject. For example:
- “I am not used to living in the city.”
- “He wasn’t used to so much work.”
- “Are you used to living with roommates?”
Get used to
Get used to has a slightly different meaning from be used to; get here means become. In fact, in more formal English, it is considered preferable to say become used to instead. In everyday speech and writing, however, get used to is perfectly acceptable.
We often use get used to in the present continuous tense. For example:
- “I am getting used to living in the city.” (I am becoming accustomed to living in the city.)
- “He is getting used to public speaking. (He is becoming accustomed to the act of public speaking.)
We can also use get used to in the past simple tense, but usually in negative constructions with the word never, as in:
- “She never got used to the silence of the countryside.”
Often, we use get used to with the modal verbs could, will, and cannot (or can’t). Could is used to create a hypothetical scenario, will creates the future tense (often paired with never), and cannot is used to mean “unable.” For example:
- “I can’t get used to working so many hours. I am so tired.” (I am unable to become accustomed to this.)
- “I could get used to doing nothing all day.” (This is something that I could find easy to do.)
- “I will never get used to these cramped conditions.” (At no point in the future will I become accustomed to this.)
Ought to is considered semi-modal because, like used to, it ends in to and so makes verbs infinitive. It is commonly compared to should because it expresses that something is viewed as correct, preferable, or necessary—or as probable, likely, or expected. It can also be used to ask for or offer advice about something.
- “With the cost of airfares so high, in-flight meals ought to be free.” (It is correct or preferable that the meals be free.)
- “We ought to arrive in the evening.” (It is probable or expected that we’ll arrive in the evening.)
- “I think we ought to turn back.” (Turning back is the necessary or best course of action—worded as advice.)
- “You ought to see the Grand Canyon some day.” (It is my advice or recommendation for you to visit the Grand Canyon.)
When ought to is made negative, not comes between ought (sometimes contracted as oughtn’t) and to; it is common to omit to when ought to is used with not. For example:
- “You ought not to read in such dim light.”
- “We oughtn’t leave the house; it isn’t safe.”
We can also form questions by inverting ought with the subject; this is not very common, though. Again, to is sometimes omitted in this form. For example:
- “Ought we find someplace to eat?”
- “Oughtn’t she study for her exam?”
- “Ought they to be more worried about the storm?”
- “Ought not he to finish his homework first?”
Ought to is becoming far less common than should in modern English, especially in American English.
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