Can, Could, Must, Etc. _Devil Stars

8/4/2019 Can, Could, Must, Etc. _Devil Stars

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Can, Could and (be) able to

Can

Be able to Ability possible allowed

E.g. I can swim.

E.g. I am able to swim. “can” is more usual

E.g. You can see a beautiful if you open the window. (possible)

E.g. She can take me to her heart. (allowed)

E.g. I can cook very well. (ability)

If you want to make negative, you can write “can’t or cannot”.

E.g. I am very sad that you can’t come to my birthday.

When we cannot use “CAN”, we have to use “BE ABLE TO”.

Present Perfect [can (present) and could (past), no present perfect form for “can”]

E.g. I haven’t been able to sleep recently.

If there is a Helping Verb (or) Auxiliary Verb in a sentence, we cannot use “can”.

E.g. Tom might be able to come tomorrow.

Can (present) = Could (past) using with see hear smell taste feel remember understand

Could general ability

E.g. My grandfather could speak five languages.

Was/were able to (or) managed to specific situation (when we get ‘permission’)

E.g. We didn’t know where David was, but we managed to find/were able to find him in the end.

Negative for “could”: couldn’t (for all situations)

E.g. My grandfather couldn’t swim.

Could (do) and could have (done)Can(present) Could (past)

Could = possible action now or future (suggestion)

Can (more sure) = Could (less sure)

E.g. A: What shall we do this evening?

B: We could go to the cinema. (suggestion)



Could (for unreality) and Can (for reality)

E.g. I can stay with Julia when I go to Paris. (realistic)

E.g. This is a wonderful place. I could stay here for ever. (unrealistic)

Could = May = Might

E.g. The story could be true, but I don’t think it is.

Could have done is the past of “could”. E.g. I was so tired, I could have slept for a week.

Could have happened is the past of “could” but it did not happen.

E.g. Dave was lucky. He could have hurt himself when he fell, but he was OK.

Couldn’t (present) = Couldn’t have done (past)

(impossible action now or future)

E.g. I couldn’t live in a big city. I’d hate it.

E.g. We had a really good holiday. It couldn’t have been better.

Must and can’t

Must (you believe something is certain)

E.g. I am sure Sally gave me her phone number. I must have it somewhere.

Can’t (you believe something is not possible)

E.g. They haven’t lived her for very long. They can’t know many people.

I/You/he (etc.) Must (or) Can’t

Be [Adjectives (or) Places]

Be [V ing]

Do/get/know/have etc.

“Can’t have done” is the past of “can’t”.

E.g. Sue hasn’t contact me. She can’t have got my message.

“Must have done is the past of “must”.

E.g. I didn’t hear the phone. I must have been asleep.

I/You/he (etc.) Must (or) Can’t Have

Been [Adjectives (or) Places]

Been [V ing]

Eaten/slept/drunk etc.

Can’t have done = Couldn’t have done in this situation.

E.g. Sue can’t have got my message.

E.g. Sue couldn’t have got my message.

May and Might 1

May (or) Might (possibility)

E.g. It may be true. (or) It might be true.



May not and might not (mightn’t) are for the negatives.

E.g. It may not be true. (or) It might not (mightn’t) be true.

I/We/They (etc.) May (or) Might (not)

Be [Adjectives (or) Places]

Be [V ing]

Play/like/smile etc.

“May have done” is the past of “may”.

E.g. A: I wonder why Kate didn’t answer the phone.

B: She may have been asleep.

“Might have done” is the past of “might”.

E.g. A: I can’t find my bag anywhere.

B: You might have left it in the shop.

He/ She/ It (etc.) May (or) Might (not) have

Been [Adjectives (or) Places]

Be [V ing]

Known/written/read etc.

Could = May (or) Might

E.g. It’s a strange story, but it could be true.

You could have left your bag in the shop.

Couldn’t≠May not (or) Might not

E.g. Sarah couldn’t have got my message. Otherwise she would have replied.

I wonder why Sarah hasn’t replied to my message. I suppose she might not have got it.

May and might 2

May (or) Might (possible actions or happenings in the future)

E.g. Take an umbrella with you. It might rain later.

Negative forms of May (or) Might are “May not and Mightn’t”.

E.g. Liz may not go out tonight. She is ill.

There might not be enough time to discuss everything at the meeting.

Will (for sure) = May (or) Might (possible)

E.g. I will be late this evening.

I may/might be late this evening.

Might (not real)

E.g. If I were in Tom’s position, I might look for another job.

Continuous Form: “may/might be –ing” and “will be –ing”.

E.g. I am going to Ireland in July.

I may be going (or I might be) to Ireland in July.



Might as well = Possible

We might as well do something We should do something (no better alternative, no reason not to do

it)

E.g. A: What time are you going out?

B: Well, I’m ready, so I might as well go now.

Have to and must

Have to = necessary (or) obliged

E.g. You can’t turn right here. You have to turn left. (obliged)

I have to wear glasses for reading. (necessary)

In questions and negative sentences do and does (present)

E.g. What do you have to do to get anew driving license?

Karen doesn’t have to work Saturdays.

In questions and negative sentences did (past)

E.g. Why did you have to leave early?

My friends didn’t have to do homework.

Will/may/might + have to

E.g. If the pain gets worse, you will have to go the doctor.

I might/may have to work late tomorrow evening.

Must = Have to

E.g. It is later than I thought. I must/have to go.

Must *to give own opinion and to recommend someone to do something* You can use “have

to” if you want.

E.g. I haven’t spoken to Sue for ages. I must phone her.

Have to (obliged to do) *a fact*

E.g. I have to work from 8.30 to 5.30 every day.

Must *for rules and instructions*

E.g. You must write your answers in ink.

No past tense for must, so we have to use “had to” for the past.

E.g. We had to leave early.

Mustn’t ≠ Don’t have to

Mustn’t = it is absolutely necessary that you do Don’t have to = you don’t need to do it but you can do if you

not do it want

E.g. You must keep it a secret. You mustn’t tell E.g. You don’t have to cook chicken curry, but if you want to

anyone. eat, you can cook.



Have to = Have got to

E.g. When has Liz got to go? (or) When does Liz have to go?

Must mustn’t needn’t

Must it is necessary to do it

E.g. You must obey the school rules.

Mustn’t it is necessary not to do it

E.g. Students mustn’t smoke in the class.

Needn’t you don’t need to do it, but you can if you want

E.g. You can join with us but you needn’t join if you don’t want to.

Needn’t = doesn’t/don’t need

E.g. I needn’t to be angry. (or) I don’t need to be angry.

“Needn’t have done” is the past of “needn’t but they are completely different.

E.g. You needn’t write the notes down. It’s OK. (You don’t do it)

You needn’t have written the notes down. (but you did it)

“Didn’t need to (do)” and “Needn’t have (done)” are for the past tense form.

Didn’t need to (do) it’s not necessary and *I knew it* (so, I didn’t do it)

E.g. I didn’t need to get up early, so I didn’t.

Needn’t have (done) it’s not necessary and *I didn’t knew it* (so, I did it but I know it now) E.g. I needn’t have to get up early, but I did because I didn’t know it.

Should 1

Should It is good thing to do give

It is right thing to do *Advice or Opinion*

E.g. You look hungry. You should eat some food.

“Should we invite Susan to the party?” “Yes, I think we should.”

I think/I don’t think/Do you think + should:

E.g. I think my teacher should punish me.

Shouldn’t do something it isn’t a good thing to do:

E.g. I shouldn’t forgive him because he is guilty.



“Must” and “Have to” are stronger than “Should”.

E.g. You should forgive.

You must forgive. (or) You have to forgive.

Should When something is not right

E.g. She isn’t here yet, and this is not normal. She should be here by now.

Should What you expect

E.g. I wonder where Tina is. She should be here by now.

Should Expect something to happen

E.g. She has been studying hard for the exam, so she should pass. (=I expect her to pass)

Should Have (done) It would have been the right thing to do but you didn’t do it

E.g. I wonder why they’re so late. They should have arrived long ago.

Shouldn’t Have (done) It was the wrong thing to do but you did it

E.g. I am feeling sick. I shouldn’t have eaten so much.

Ought to = should (ought to do)

E.g. Do you think I ought to/should apply for this job?

Should 2

Should + demand insist propose recommend suggest

E.g. I demanded that he should apologize.

What do you suggest I should do?

It’s important vital necessary essential + that ……. Should…..:

E.g. It is essential that everyone should be here on time.

It is essential that everyone is here on time. (extra example)

It is essential that everyone should be here on time.

It is essential to be here on time. (extra example) (to + affirmative verb)

After “suggest” we cannot use the form of “to + affirmative verb”.

E.g. I suggest that everyone should be here on time.

I suggest that everyone is here on time.

I suggest that everyone should be here on time.



I suggest that being here on time.

I suggest everyone to be here on time.

A number of adjectives we can leave out

A number of verbs SHOULD

Especially: strange, odd, funny, typical, natural, interesting, surprised, surprising

E.g. I am surprised that he should say such a thing.

If………. should………….

E.g. If it rains, we won’t go out.

We can use “Should” instead of “if”.

E.g. Should it rain, we won’t go out.

Should ……… / Should ………….: to give somebody “advice”

E.g. A: Shall I leave now?

B: No, I should wait a bit longer if I were you.

Had better It’s time…………

You’d better do something (give advice) there will be a problem or a danger if you don’t do it. E.g. We had better to stop for petrol soon. The tank is almost empty.

Negative form of “had better” is “had better not”. (had not better )

E.g. You don’t look very well. You had better not to go to work today.

For Spoken English: You’d better…. / I’d better…. Etc.

E.g. “Are you going out tonight?” “I’d better not. I’ve got a lot to do.”

Had better specific situation = should all types of situations

“had better” means that “there is always a danger of a problem if you don’t do it” but “should” means that “it

is a good thing to do”.

E.g. It is late. You’d better go. / You should go. (specific situation)

You’re always at home. You should go out more often. (general situation – not had better go)



It’s time….

E.g. It’s time to go home.

It’s time for us to go home. =

It’s time we went home.

* It doesn’t mean “past”. It is for the present.* (Should have done)

It’s about time: makes the criticism stronger

E.g. Jack is a great talker. But it’s about time he did something instead of just talking.

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Can, Could, Must, Etc. _Devil Stars