1. Modal Verbs

(A) What are Modal Verbs?

(1) Modal Verbs are: must / can / could / may / might / will / would / shall / should / ought to

(2) We can't add: -s / -ing or -ed to them like other verbs.

  • Simple Explanation: Modal verbs never change their form. You cannot add "s," "ing," or "ed" to them.
  • New Example: She must study hard. (NOT: She musts study hard)
  • New Example: She had to study hard.

(3) Modal verbs are followed by (infinitive without to).

  • Simple Explanation: After a modal verb, use the base form of the verb (without "to").
  • New Example: Tom may be late to the lecture today.
  • New Example: You have to see a doctor. You look terribly ill.

(4) Use perfect infinitive (Have + P.P.) after Modal Verbs to make the past tense.

  • Simple Explanation: To talk about the past using a modal verb, use "have + past participle."
  • New Example: You shouldn't have left the door unlocked. That was your mistake.
  • New Example: Tom must have been very angry yesterday.

(5) Modal verbs can be used as helping verbs to form questions and negation.

  • Simple Explanation: Modal verbs can be used to ask questions or make negative sentences.
  • New Example: Can I talk to Mr. Hamdy?
  • New Example: Sorry, he can't take phone calls now.
  • New Example: Should we come every day at 7 in the morning?

(6) Modal verbs can refer to the present, the future or the past according to the meaning and structure of the sentence, not the form of the modal verb itself.

  • Simple Explanation: The time (past, present, future) depends on the context, not the modal verb form.
  • New Example: This is his car. He must be at home now. (Present)
  • New Example: His car isn't here. He must have left. (Past)
  • New Example: They may come back tomorrow. (Future)

(7) Modal verbs are used to express meanings like:

  • obligation / necessity / certainty / permission / prediction / requests / prohibition: must, have to, should, can, will, may
  • suggestions / lack of necessity / possibility / ability / offers / speculation / advice: shall, needn't, can, could, may, might, would

(8) One modal verb can be used to express more than one meaning.

  • New Example: You must have been tired at the end of the race. (speculation)
  • New Example: You must study harder for the exam. (obligation)
  • New Example: You mustn't exceed the speed limit. (prohibition)

(B) Functions of Modal Verbs

(1) Ability [can – could]

  • New Example: Tom can play the guitar perfectly.
  • New Example: I could run fast when I was young.
  • Notes:
    • I wasn't able to know his home address. (Use: could)
    • I couldn't know his home address.
    • She can paint the house on her own. (Use: able)
    • She is able to paint the house on her own.

(2) Obligation & Necessity [must – have to]

  • New Example: You must listen carefully to your teacher.
  • New Example: You have to be at the airport at 9 o'clock.
  • Notes:
    • You are obliged to respect your teachers. (Use: must)
    • You must respect your teachers.
    • It's important for me to get up at six o'clock daily. (Use: have to)
    • I have to get up at six o'clock every day.
    • It was necessary for my father to travel yesterday. (Use: had to)
    • My father had to travel yesterday.

(3) Lack of necessity [needn't – (not) have to]

  • New Example: You don't have to answer all the questions.
  • New Example: You needn't answer all the questions.
  • New Example: The store is locked today. You needn't have come.
  • Notes:
    • It isn't necessary for us to wear school uniform. (Use: have to)
    • We don't have to wear school uniform.
    • It isn't necessary for Sam to do the exam again. (Use: needn't)
    • Sam needn't do the exam again.
    • It wasn't necessary for you to bring all the books. (Use: needn't)
    • You needn't have brought all the books.

(4) Prohibition [mustn't – can't]

  • New Example: You mustn't drive over 100 km/h.
  • New Example: You can't use the front door. It's for the staff members only.
  • Notes:
    • You aren't allowed to go in because you are under 18. (Use: can't)
    • You can't go in because you are under 18.
    • Using the front door is forbidden for pupils. (Use: can't)
    • Pupils can't use the front door.
    • We aren't allowed to use the phone for private calls. (Use: can't)
    • We can't use the phone for private calls.
    • It is very important not to forget your medicine. (Use: mustn't)
    • You mustn't forget your medicine.

(5) Speculation [must – can't]

  • New Example: It is Sunday. He must be at home.
  • New Example: His car isn't in the garage. He can't be at home.
  • New Example: Tom didn't come to school. He must have been ill.
  • New Example: I didn't see you there. You can't have come.
  • Notes:
    • I'm sure your daughter is very nice to you. (Use: must)
    • Your daughter must be very nice to you.
    • I didn't have your letter. You surely made a mistake. (Use: must)
    • I didn't have your letter. You must have made a mistake.
    • I am sure you didn't paint the house yourself. (Use: can't)
    • You can't have painted the house yourself.

(6) Future Prediction [will – might – may]

  • New Example: I think I will go to the party tomorrow. (certain)
  • New Example: I am not sure yet. I may go to Ireland in the summer. (perhaps I will go)
  • New Example: Take an umbrella with you. It might rain later. (perhaps it will rain)
  • Notes:
    • "will" = I'm sure, it's certain that, it's definite that
    • "may" & "might" = I'm not sure, it's possible that – it is likely to
    • It's likely to rain this afternoon. (Use: might)
    • It might rain this afternoon.
    • I am not sure yet if I can come to the party. (Use: may)
    • I may come to the party.
    • It's possible that we win the match. (Use: might)
    • We might win the match.

(7) Possibility [can – could – may – might]

  • New Example: Bob may be in his office.
  • New Example: Bob might be having lunch.
  • New Example: The roads could get very busy tomorrow because of the match.
  • Notes:
    • Perhaps Tom is in his office. (may)
    • Tom may be in his office.
    • Bob might be having lunch with Jane. (Perhaps)
    • Perhaps Bob is having lunch with Jane.
    • Ask Ann about it. She might know something. (Perhaps)
    • Ask Ann about it. Perhaps she knows something.
    • She didn't answer the phone. Perhaps she was asleep. (might)
    • She didn't answer the phone. She might have been asleep.
    • The roads could get very busy because of the match. (possible)
    • It is possible that the roads get very busy because of the match.
    • She may come late. (likely)
    • She is likely to come late.

(8) Permission [can – could – may – might I ...?]

  • New Example: Can I use your pen for a minute?
  • New Example: Could I use your pen for a minute?
  • New Example: May I come in?
  • New Example: Mum says I can't go out with friends.
  • Notes:
    • Mum doesn't allow me to go out with my friends. (can't)
    • Mum says I can't go out with my friends.
    • Mum says I can't go out with my friends. (let)
    • Mum doesn't let me go out with my friends.
    • Do you mind if I use your pen for a minute? (Could)
    • Could I use your pen for a minute?

(9) Making suggestions [Shall – can – could] How about? – What about? – Let's – Why don't we?

  • New Example: Shall we go to the theatre tomorrow? (How about ...?)
  • New Example: How about going to the theatre tomorrow?
  • New Example: We could go to the cinema this weekend. (Why don't we ...?)
  • New Example: Why don't we go to the cinema this weekend?

(10) Giving advice [should – ought to]

  • New Example: You should / ought to go to school early. [GENERAL ADVICE]
  • New Example: You'd better go early or you'll miss the train. [SPECIFIC SITUATION]
  • Notes:
    • If I were you, I'd find another job. (should)
    • You should find another job.
    • You should see a doctor for that headache. (had better)
    • You 'd better see a doctor for that headache.

(11) Making requests [Can – Could – Will – Would you ...?]

  • New Example: Will you get me some water please?
  • New Example: Would you type these letters for me, please?
  • New Example: Can you give me a hand with these boxes, please?

(12) Making offers [Would you like – shall I ...?]

  • New Example: You look tired. I will do the washing up for you. (Shall ...)
  • New Example: You look tired. Shall I do the washing up for you?
  • New Example: Shall I do the washing up for you? (Would you ...)
  • New Example: Would you like me to do the washing up for you?
  • New Example: Shall I do the washing up for you? (Do you ...)
  • New Example: Do you want me to do the washing up for you?