Modals and Auxiliaries
ICSE Class 8 · English · Chapter 3
What this chapter covers
- Helping verbs and main verbs
- Primary auxiliaries: be, have and do
- Modal auxiliaries and how they behave
- Ability, permission and obligation
- Possibility and deduction
- Semi-modals: used to, ought to, need and dare
- Choosing the right modal for the situation
- Common errors with auxiliaries and modals
Key points
- An auxiliary verb helps a main verb show tense, voice, mood, a question or a negative; the main verb comes last in the verb phrase.
- The primary auxiliaries are "be" (continuous tenses, passive), "have" (perfect tenses) and "do" (questions, negatives, emphasis); all three can also be main verbs.
- The modals are can, could, may, might, shall, should, will, would and must; they add ability, permission, duty, possibility or certainty.
- A modal takes the base form without "to", never adds "-s", has no "-ing" or past participle form, and makes questions and negatives without "do".
- Ability: can, could, be able to. Permission: can, could, may. Obligation: must, have to, should, ought to.
- "Must not" forbids; "don't have to" and "needn't" mean "not necessary".
- Possibility: may, might, could, can. Deduction: must (sure it is true) and can't (sure it is not true); use "must have" and "can't have" for the past.
- Semi-modals: "used to" for past habits, "ought to" for duty, and "need" and "dare" as modals mainly in questions and negatives.
- Two modals never stand together; use "be able to" or "have to" to fill the gap.
- Polite requests use "could" and "would"; formal permission uses "may".
Questions answered
What is the difference between a main verb and an auxiliary verb?
A main verb carries the chief meaning of the action or state. An auxiliary verb comes before the main verb and helps it show tense, voice, a question or a negative.
Name the three primary auxiliaries and give one use of each.
"Be" forms continuous tenses and the passive; "have" forms the perfect tenses; "do" forms questions and negatives in the simple tenses and adds emphasis.
In "They have a new car" and "They have bought a new car", which "have" is an auxiliary?
The second one, because it helps the main verb "bought". In the first sentence, "have" works as the main verb.
Correct the sentence: "My brother can drives a scooter."
"My brother can drive a scooter." A modal is followed by the base form, without "-s".
Explain the difference between "You mustn't use the lift" and "You don't have to use the lift".
"Mustn't" forbids using the lift. "Don't have to" means using the lift is not necessary, but it is allowed.
Complete with a modal of possibility or deduction: "Her phone is switched off. She ______ be in the cinema."
"may" or "might". A switched-off phone gives only a weak clue, not strong evidence, so "must" would sound too sure.
Why is "I will can come" wrong, and how should it be written?
Two modals cannot stand together. Write "I will be able to come."
Give the negative and the question form of "She used to live in Kochi."
Negative: "She didn't use to live in Kochi." Question: "Did she use to live in Kochi?"