MODAL AUXILIARIES

MODAL AUXILIARIES

CONTENTS      :

                           

1. The form of modal auxiliaries
2. Expressing ability: can and could
3. Expressing possibility: may and might

Expressing permission: may and can

4. Using could to express possibility
5. Polite questions: may I, could I, can I
6. Polite questions: would you, could you, can you
7. Expressing advice: should and ought to
8. Expressing advice: had better
9. Expressing necessity: have to, have got to, must
10. Expressing lack of necessity: do not have to

Expressing prohibition: must not

11. Making logical conclusions: must

1. THE FORM OF MODAL AUXILIARIES
The verbs listed below are called “modal auxiliaries”. They are helping verbs that express a wide range of meanings (ability, permission, necessity, etc.). Most of the modals have more than one meaning.
AUXILIARY + THE SIMPLE FORM OF A VERB	Can, could, may, might, should, had better, must, will, and would are immediately followed by the simple form of a verb. They are not followed by to. Incorrect: Olga can to speak English. The main verb does not have a final –s. Incorrect: Olga can speaks English. The main verb is not in a past form. Incorrect: Olga can spoke English. The main verb is not in its –ing form. Incorrect: Olga can speaking English.
Can            (a) Olga can speak English. Could        (b) He couldn’t drive a car. May           (c) It may rain tomorrow. Might        (d) It might rain tomorrow. Should       (e) I should study harder. Had better (f) I had better study tonight. Must          (g) Joe must see a doctor. Will           (h) I will be in class. Would       (i) Would you please open it ?
AUXILIARY + TO + THE SIMPLE FORM OF A VERB	To + the simple form is used with these auxiliaries: have to, have got to, and ought to.
Have to           (j) I have to study tonight. Have got to     (k) I have got to study tonight. Ought to          (l) Kate ought to study harder.

2. EXPRESSING ABILITY: CAN AND COULD
(a)    Bob can play the piano. (b)   You can buy a screwdriver at a hardware store. (c)    I can meet you at Ted’s tomorrow afternoon.	Can expresses ability in the present or future.
(d)   I + (can/cannot/can not) + understand that sentences.	The negative form of can may be written can’t, cannot or can not.
(e)    Our son could walk when he was one year   old.	The past form of can is could.
(f)    He couldn’t walk when he was six months old.	The negative of could: couldn’t or could not.

3. EXPRESSING POSSIBILITY: MAY AND MIGHT     EXPRESSING PERMISSION: MAY AND CAN
(a)    It may rain tomorrow (b)   It might rain tomorrow (c)    A: Why isn’t John in class? B: I don’t know. He + (may/might) + be sick today.	May and might express possibility in the present pr future. They have same meaning. There is no difference in meaning between (a) and (b).
(d)   It may rain tomorrow. (e)    It might rain tomorrow.	Negative: may not and might not. (Do not contract may and might with not).
(f)    May be it will rain tomorrow. COMPARE (g)   May be John is sick. (adverb) (h)   John may be sick. (verb)	In (f) and (g): maybe (spelled as one word) is an adverb. It means “possibly”. It comes at the beginning of a sentence. Incorrect: It will maybe rain tomorrow. In (h): may be (two words) is a verb form: the auxiliary may + the main verb be. Incorrect: John maybe sick.
(i)     Yes, children, you may have a cookie after dinner. (j)     Okay, kids, you can have a cookie after dinner.	May is also use to give permission, as in (i). Often can is use to give permission, too, as in (j). (i) and (j) have the same meaning, but may is more formal than can.
(k)   You may not have a cookie. You can’t have a cookie.	May not and cannot (can’t) are used to deny permission (i.e., to say “no”).

4. USING COULD TO EXPRESS POSSIBILITY
(a)  A: Why isn’t Greg in class? B: I don’t know. He could be sick. (b)   Look at those dark clouds. It could start raining any minute.	Could can mean past ability. But that is not its only meaning. Another meaning of could is possibility. In (a): “He could be sick” has the same meaning as “He may/might be sick”, i.e., “It is possible that he is sick.” In (a): could expresses a present possibility. In (b); could expresses a future possibility.

5. POLITE QUESTIONS: MAY I, COULD I, CAN I
POLITE QUESTION	POSSIBLE ANSWERS	People use may I, could I,* and can I to ask polite question. The questions ask for someone’s permission or agreement. (a), (b), and (c) hve basically the same meaning. Note: can I is less formal than may I and could I.
(a)  May I please borrow your pen? (b)  Could I please borrow your pen? (c)   Can I please borrow your pen?	Yes. Yes. Of course. Yes. Certainly. Of course. Certainly. Sure. (informal) Okay. (informal) Uh-huh. (meaning “yes”) I’m sorry, but I nrrd to use it myself.
		Please can come at the end of the question: may I borrow your pen, please? Please can be omitted from the question: may I borrow your pen ?

*In a polite question, could is NOT the past form of can.

6. POLITE QUESTIONS: WOULD YOU, COULD YOU, WILL YOU, CAN YOU
POLITE QUESTION	POSSIBLE ANSWERS	People use would you, could you, will you, and can you to ask polite questions. The questions ask for someone’s help or cooperation. (a), (b), (c), and (d) have basically the same meaning. The use of can, as in (d), is less formal than the others.
(a)  Would you please open the door? (b)  Could you please open the door? (c)   Will you please open the door? (d)  Can you please open the door?	Yes. Yes. Of course. Certainly. I’d be happy to. Of course. I’d be glad to. Sure. (informal) Okay. (informal) I’m sorry. I’d like to help, but my hands are full.
		Note: May is NOT use when you is subject of polite question. Incorrect: May you please open the door?

7. EXPRESSING ADVICE: SHOULD AND OUGHT TO
(a)  My clothes are dirty. I (should/ ought to) wash them. (b)  Incorrect: I should to wash them. (c)   Incorrect: I ought washing them.	Should and ought to have the same meaning. They mean: “This is good idea. This is good advice.” Forms: Should + simple form of a verb (no to) Ought + to + simple form of a verb
(d)  You need your sleep. You should not (shouldn’t) stay up late.	Negative: should + not = shouldn’t (Ought to is usually not use in the negative.)
(e)  A: I’m going to be late. What should I do ? B: Run.	Question: should + subject + main verb (Ought to is usually not use in question)
(f)    A: I’m tired today. B: You should/ought to go home and take a nap. (g)  A: I’m tired today. B: Maybe you should/ought to go home and take a nap.	The use of maybe with should and ought to “softens” advice. Compare: In (f): Speaker B is giving definite advice. He is stating clearly that he believes going home for a nap is a good idea and is the solution to Speaker A’s problem. In (g): Speaker B is making a suggestion: going home for a nap is one possible way to solve Speaker A’s problem.

8. EXPRESSING ADVICE: HAD BETTER
(a)  My clothes are dirty. I (should/ ought to/had better) wash them. (b)  You’re driving to fast! You’d better slow down.	Had better has the same basic meaning as should and ought to: “This is a good idea. This is good advice.”
	Had better usually implies a warning about possible bad consequences. In (b): If you don’t slow down, there could be a bad result. You could get a speeding ticket or have an accident.
(c)   You’d better not eat that meat. It looks spoiled.	Negative: Had better not
(d)  I’d better send my boss an e-mail right away.	In speaking, had is usually contracted: ‘d.

9. EXPRESSING NECESSITY: HAVE TO, HAVE GOT TO, MUST
(a)  I have a very important test tomorrow. I (have to/ have got to/ must) study tonight.	Have to, have got to, and must have basically the same meaning. They express the idea that something is necessary.
(b)  I’d like to go with you to the movie this evening, but I can’t. I have to go to a meeting. (c)   Bye now! I’ve got to go. My wife’s waiting for me. I’ll call you later. (d)  All passengers must present their passports at customs upon arrival.	Have to is use much more frequently in everyday speech and writing that must. Have got to is typically used in informal conversation, as in (c). Must is typically found in written instructions, as in (d). It is usually a strong, serious, “no nonsense” word.
(e)  Do we have to bring pencils to the test? (f)    Why did he have to leave so early?	Questions: Have to is usually used in questions, not must or have got to. Forms of do are used with have to in questions.
(g)  I had to study last night.	The past form of have to, have got to, and must (meaning necessity) is had to.

10. EXPRESSING LACK OF NECESSITY: DO NOT HAVE TO EXPRESSING PROHIBITION: MUST NOT
(a)  I finished all of my homework this afternoon. I don’t have to study tonight. (b)  Tomorrow is a holiday. Mary doesn’t have to go to class.	Don’t/doesn’t have to expresses the idea that something is not necessary.
(c)   Children, you must not play with matches! (d)  We must not use that door. The sign says private: do not enter.	Must not expresses prohibition (DO NOT DO THIS!)
(e)  You mustn’t play with matches.	Must + not = mustn’t. (Note: The first “t” is not pronounced.)

11. MAKING LOGICAL CONCLUSIONS: MUST
(a)  A: Nancy is yawning. B: She must be sleepy.	In (a): Speaker B is making a logical guess. He basses his guess on the information that Nancy is yawning. His logical conclusion, hi “best guess”, is that Nancy is sleepy. He use must to express his logical conclusion.
(b)  Logical conclusion: Amy plays tennis everyday. She must like to play tennis. (c)   Necessity: If you want to get into the movie theater, you must buy a ticket.	Compare: Must can express A logical conclusion, as in (b). Necessity, as in (c).
(d)  Negative logical conclusion: Eric ate everything on his plate except the pickle. He must not like pickles. (e)  Prohibition: There are sharks in the ocean near our hotel. We must not go swimming there.	Compare: Must not can to express A negative logical conclusion, as in (d). Prohibition, as in (e).