Also called helping verbs. They have no meaning on their own. They are necessary for the grammatical structure of a sentence, but they do not tell us very much alone. We usually use helping verbs with main verbs. They "help" the main verb (which has the real meaning).
Auxiliary Verbs
There are only about 15 helping verbs in English, and we divide them into two basic groups:
Primary helping verbs (3 verbs). These are the verbs be, do, and have.
Note that we can use these three verbs as helping verbs or as main verbs.
Primary helping verbs
Uses of “be”
1. Simple Questions
We create simple yes/no questions by inverting the order of subject and the “To be” verb.
Is your brother taller than you?
Were they embarrassed by the comedian?
The same inversion takes place when “To be” is combined with verbs in the progressive:
Is it snowing in the mountains?
Were your children driving home this weekend?
Primary helping verbs
2. In Passive Constructions
A form of the verb “To be” is combined with a past participle to form the passive.
The “To be” will also change to indicate the time of the action and the aspect of the verb (simple, progressive, perfect).
Primary helping verbs
3. Progressive Forms
¡ Progressive forms include a form of “To be” plus a present participle (an -ing ending).
¡ to describe actions already in progress at the moment "in focus" within the sentence, as in “I was doing my homework when my brother broke into my room, crying.” or “I will be graduating from college about the same time that you enter high school.”
¡ Primary helping verbs
4. Tag Questions with “To Be”
When we use “To be” verbs in a tag question, the basic formula follows: the verb is combined with a pronoun and sometimes with not (usually in a contracted form). Positive statements are followed by negative tags; negative statements by positive tags.
¡ Primary helping verbs
¡ Uses of Do, Does and Did
¡ In the simple present tense, do will function as an auxiliary to express the negative and to ask questions. (Does, however, is substituted for third-person, singular subjects in the present tense. The past tense did works with all persons, singular and plural.)
¡ Primary helping verbs
¡ With "yes-no" questions, the form of do goes in front of the subject and the main verb comes after the subject:
¡ Did your grandmother know Truman?
¡ Do wildflowers grow in your back yard?
¡ Primary helping verbs
¡ Forms of do are useful in expressing similarity and differences in conjunction with so and neither.
¡ My wife hates spinach and so does my son.
¡ My wife doesn't like spinach; neither do I.
¡ Primary helping verbs
¡ Do is also helpful because it means you don't have to repeat the verb:
¡ Larry excelled in language studies; so did his brother.
¡ Raoul studies as hard as his sister does.
¡ Primary helping verbs
¡ The so-called emphatic do has many uses in English.
¡ To add emphasis to an entire sentence: "He does like spinach. He really does!"
¡ To add emphasis to an imperative: "Do come in." (actually softens the command)
¡ To add emphasis to a frequency adverb: "He never did understand his father." "She always does manage to hurt her mother's feelings."
¡ Primary helping verbs
To contradict a negative statement: "You didn't do your homework, did you?" "Oh, but I did finish it."
To ask a clarifying question about a previous negative
statement: "Ridwell didn't take the tools." "Then who did take the tools?"
To indicate a strong concession: "Although the Clintons
denied any wrong-doing, they did return some of the gifts."
In the absence of other modal auxiliaries, a form of do is used in question and negative constructions known as the get passive:
Did Rinaldo get selected by the committee?
The audience didn't get riled up by the politician.
¡ Primary helping verbs
¡ Uses of Have, Has and Had
¡ Forms of the verb to have are used to create tenses known as the present perfect and past perfect. The perfect tenses indicate that something has happened in the past; the present perfect indicating that something happened and might be continuing to happen, the past perfect indicating that something happened prior to something else happening.
¡ Primary helping verbs
¡ To have is also in combination with other modal verbs to express probability and possibility in the past.
¡ As an affirmative statement, to have can express how certain you are that something happened (when combined with an appropriate modal + have + a past participle)
¡ Primary helping verbs
¡ As a negative statement, a modal is combined with not + have + a past participle to express how certain you are that something did not happen: "Clinton might not have known about the gifts."
¡ Primary helping verbs
¡ Have is often combined with an infinitive to form an auxiliary whose meaning is similar to "must."
¡ I have to have a car like that!
¡ She has to pay her own tuition at college.
¡ He has to have been the first student to try that.
¡ Modal Auxiliaries
¡ Can We use can to:
¡ talk about possibility and ability
¡ make requests
¡ ask for or give permission
¡ Modal Auxiliaries
¡ Use of Could
¡ could: Past Possibility or Ability
¡ could: Requests
¡ Be able to
¡ Modal Auxiliaries
¡ May & Might
¡ May
¡ Talking about things that can happen in certain situations
¡ Might
¡ Saying that something was possible, but did not actually happen
¡ Modal Auxiliaries
¡ Will
¡ Talking about the present, future or past with certainty
¡ Making a decision
¡ Making a semi-formal request
¡ Insistence; habitual behaviour
¡ Making a promise or a threat
¡ Modal Auxiliaries
¡ Shall
¡ Making offers
¡ Making suggestions
¡ Duty
¡ Modal Auxiliaries
¡ Would
¡ Polite requests and offers (a 'softer' form of will)
¡ In conditionals, to indicate 'distance from reality': imagined, unreal, impossible situations
¡ After 'wish', to show regret or irritation over someone (or something's) refusal or insistence on doing something (present or future)
¡ Modal Auxiliaries
¡ Would
¡ Talking about past habits (similiar meaning to used to)
¡ Future in the past
¡ After 'wish', to show regret or irritation over someone (or something's) refusal or insistence on doing something (present or future)
¡ Modal Auxiliaries
¡ Must
¡ Necessity and obligation
¡ Strong advice and invitations
¡ Saying you think something is certain
¡ Modal Auxiliaries
¡ Should
¡ Giving advice
¡ Obligation: weak form of must
¡ Things which didn't or may/may not have happened
¡ Modal Auxiliaries
¡ Ought to Ought to usually has the same meaning as should, particularly in affirmative statements in the
¡ present:
You should/ought to get your hair cut.
Should is much more common (and easier to say!), so if you're not sure, use should.
Modal Auxiliaries
¡ Used to
The auxiliary verb construction used to is used to express an action that took place in the past, perhaps customarily, but now that action no longer customarily takes place:
We used to take long vacation trips with the whole family.
Modal Auxiliaries
¡ Used to can also be used to convey the sense of being accustomed to or familiar with something:
¡ The tire factory down the road really stinks, but we're used to it by now
¡ I like these old sneakers; I'm used to them.
¡ Used to is best reserved for colloquial usage; it has no place in formal or academic text.
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