I always say the verb in English is the laziest in existence. It hardly does anything. It leaves the hard work to the auxiliaries/modals/tools.

The modals have a wide range of uses and concepts according to context and must be thoroughly drilled. They can be divided into types but I don’t want to go into all that here:

can  may  shall  will  could  might

should  would  must  ought to  used to

need  needn’t  dare  daren’t  had better

tend to(?)  would rather  can’t  couldn’t  have got to

do  does  did

The modal auxiliary tools have various roles:

1. i. a conceptual role

The simple tool “can” can be deceptive; it denotes that a learning process has been completed and the person now knows how to carry out the skill. He can carry out the skill. “He can swim” literally means he won’t drown in deep water. However “he can drive” is more complex. He has completed a course, passed a test and received a permit, so he can drive (intellectually) and he can drive (legally) and he hasn’t got any physical disability (broken arm) and so he can drive (physically). Obviously he can’t swim if there isn’t any water for him to swim in.

1. ii. the geographical role

Obviously you have to be in a certain place to be able to see a certain thing, so we say “I can see it” is geographical. It hasn’t been learnt. Similarly “I can hear it” means “I’m within hearing distance of the source of the sound”.

“I can understand it” and “I can appreciate it” and so on are variations.

1. iii. By far the most important role is the future role.

“I can finish it later”

However this simple sentence throws up one of the most difficult problems in the English language. The past form of “can” is “could” but we mustn’t forget that “can” and “could” replace “am able to/is able to/are able to” and “was able to/were able to” in the present and past forms respectively. The explanation is “ubiquity”. It is much more economic to replace “I am able to swim” or “I was able to swim” with “I can swim” and “I could swim”: similarly, “I can see it” or “I could see it”. The problem lies with “could” which is also used conditionally as a future, so “I can finish it later” and “I could finish it later” are both futures. To put “I can finish it later” into the past, we step back to the original verb “to be able” and use “was able to/were able to”.  Thus the past of “I can finish it later” would be “I was able to finish it later”. If an adverb of time is used, then we have “I can finish it next week” and “I was able to finish it last week”. If we use “could” in this example, it would remain in the future “I could finish it next week” (conditional).

Of course, unlike many other languages, the negative in the English language is almost always made by using an auxiliary modal tool with the negative tool “not” carried on its back (often as not, “not” is contracted or as in the case of “will not” which is rewritten as “won’t”)

Thus we have the negative tool for all tenses:

can’t  may not  shan’t  won’t  mightn’t  shouldn’t  wouldn’t  mustn’t  oughtn’t to  needn’t (needs an explanation)  daren’t (also needs an explanation)  had better not  tend not to  would rather not  haven’t got to  hasn’t got to. Used to is really a semi-modal; its negative follows the verb form-didn’t use to.

As we see with “tend not to”, the negative is placed before infinitives without a contraction “Remind me not to lend him anything again” and before the gerund “he was sent to prison for not paying the fine”. Otherwise in simple sentences the modal is followed by the infinitive minus the particle “to”-

“I can swim”, “I couldn’t see it”.

The interrogative is usually made by inverting subject and auxiliary modal “can you swim?”, “did he win?””What did he do?” (exception: what happened?)

This simple system however, when we advance to what I call the TRUE MODALS, changes radically.

If we remember that Transitive Verbs take the passive and intransitive verbs do not, a transitive verb like “take” would have the following forms of the infinitive.

full infinitive:

to take

to be taking

to be taken

to have taken

to have been taking

to have been taken

bare infinitive:

take

be taking

be taken

have taken (‘ve taken)

have been taking (‘ve been taking)

have been taken (‘ve been taken)

The True Modals take the bare infinitive in the present and the perfect form for the past, the true modal doesn’t change. Thus

I should take (present)

I should be taking (present continuous)

I should be taken (present passive)

I should have taken (past)

I should have been taking (past continuous)

I should have been taken (past passive)

In spoken English we always or nearly always contract where possible. Thus might’ve/ could’ve / should’ve  and so on are completely acceptable in spoken English. Even I’d’ve helped if you’d helped is completely acceptable.

The modals that take the True Modal Forms are

might/may/could

could

should

should

should

should

should

‘d better

‘d better

must (mustn’t)

can’t

needn’t

‘d rather

The conceptual use is the hardest part to assimilate. So drilling and examples are required; NOT just an explanation.

may/might/could

Three modals are used to express supposition where there are various possibilities.

could

Here it is the conditional and is used to describe future physical possibility.

should

1^st.person singular and plural to express “confession”

should

2^nd. singular and plural to express “light advice”. In the negative it expresses “admonition”.

should

3^rd. person singular and plural to express “opinion”.

should

To express supposition for logical expectation.

should

To express unfulfilled expectation.

‘d better

Strong advice or warning. NO past. Perfect form denotes termination.

‘d better

Threat. NO past. Perfect form denotes termination.

must (mustn’t)

This modal is used to express supposition where only one possibility exists.

can’t

This modal is used to express supposition for impossibility.

needn’t

In the present it is a substitute for don’t/doesn’t need + infinitive.

However the past (needn’t have + past participle) is NOT the equivalent of “didn’t need to”.

‘d rather

This modal is a substitute for prefer + infinitive. It saves one syllable (to). In the past it is similar to “needn’t” in that an action took place which was a mistake and the modal expresses futility or regret.

The great advantage of The True Modals is that they don’t change with the subject noun singular or plural. The verb form remains the same with al subject pronoun form including “one” and with possessives. The past is expressed not in the modal but in the perfect infinitive. So, always thinking conceptually of what we want to say, we can express the following:

subject

Tom/the children/I/you/he/she/it/we/they/one/everyone/somebody/there/noun clauses/noun phrases/clauses + relative clause………………….and so on

true modal

may/might/could/could/should (ought to)/should/should/should/should/’d better (no past)/

’d better (no past)/must/can’t/needn’t/’d rather

“Sevens” Present

1. 1. be
2. 2. wear (all verbs)
3. 3. be –ing
4. 4. be able to
5. 5. have
6. 6. be
7. 7. have to

“Sevens” Past

1. 1. (to be) have been
2. 2. (all verbs) have worn
3. 3. (continuous) have been –ing
4. 4. (ability) have been able to
5. 5. (possession) have had
6. 6. (existential) have been
7. 7. (obligation) have had to

Note: the Conditional tool “would” uses the same construction (would buy/would have bought)

Note: to be (supposed to) uses the same form but for termination (you’re supposed to finish at six/you’re supposed to have finished)

Now let’s get onto some examples!

1. 1. He might be a spy. He might have been a spy.
2. 2. You could go to Paris by train. You could have gone to Paris by train.
3. 3. He should be arriving in Paris at any minute. He should have been arriving in Paris half an hour ago.
4. 4. She’d better be able to make the beds properly next time. (2) She’d better have made the beds when I get back (completion, NOT past).
5. 5. They must have more money than Bill Gates. They must have had more money than Bill gates.
6. 6. There can’t be ten people in the car. There can’t have been ten people in the car.
7. 7. She needn’t have to wear different shoes every day (complaint). She needn’t have had to wear different shoes every day (but she did).

2. We’d rather eat in a McDonald’s (instead of a pizza bar). We’d rather have eaten in a McDonald’s (but we ate elsewhere).

I know you are thinking, “But why call it a True Modal?” Well, why not? The fact that it has an abstract concept and a present and past form is TRUE. So, why not?

The tool COULD might shine a little light or darkness on the problem;

as a True Modal

as a Simple Modal

as an Auxiliary

as a Defective/Substitute

“Could” as True Modal

The man in the corner could need help. (might need/may need)

The man in the corner could have needed help. (might have needed/may have needed)

They could hire a car.

They could have hired a car.

“Could” as a Simple Modal

Polite imperative:

Could you open the window, please? (can you open?/will you open?/would you open?)

Request:

Could I borrow it, please? (may I borrow?/can I borrow?)

Polite imperative from authority:

Could I see your license, please? (can I see?/may I see?)

Meaning “usually was”:

The late King could be very obstinate.

Polite request/permission:

Could I sit here for a few minutes? (may I sit?/can I sit?)

Admonition:

You could look where you’re going!

“Could” as an Auxiliary

If you buy a lottery ticket, you could be a millionaire next week.

If you had bought a lottery ticket, you could have been a millionaire by now.

If I could drive, I could escape.

If I’d been able to drive, I could have escaped.

“Could” as a Defective/Substitute

Past learnt ability:

I could read before I went to school.

Past geographical ability:

I could see it from the hotel.

Future in the past:

I was able to retrieve it with a stick but I couldn’t retrieve it with a stick.

Now let’s look at the rest!

“May”  as True Modal

He may be ill.

He may have been ill.

“May” as Simple Modal

Request:

May I have another apple?

Polite imperative from authority:

May I see your driving license?

Permission:

May I sit here?

Exhortation:

May the best man win!

“May” as an Auxiliary

Substituting “will”:

I may go to the cinema.

If it rains, he may come by taxi.

“Might” as True Modal

He might know the way.

He might have known the way.

“Might” as Simple Modal

Formal admonition:

Might I ask what you are doing!

Admonition:

You might look where you’re going!

“Might” as an Auxiliary

I might go to London next year.

If she sees a doctor, she might live forever.

“Should” as True Modal

I should be more patient.

I should have been more patient.

You should relax more.

You should have relaxed more.

He should read “The Times”.

He should have read “The Times”.

They should be there by now.

They should have been there an hour ago.

He should speak it better.

He should have spoken it better.

“Should” as Simple Modal

Unlikely Conditional:

If you should see one, could you ask how much it costs?

Unlikely Inverted Conditional:

Should you see him, give him my regards.

Putative:

He suggested that we should wait a little longer.

“’d better” as True Modal

Strong Motive:

I’d better take an umbrella.

Strong Advice/Motive:

You’d better see a doctor.

Indirect Advice:

He’d better stay in bed.

Threat:

You’d better not move.

“’d better” as an Auxiliary

If the forecast says there’ll be storms, we’d better stay at home.

“Must” as True Modal

You must be mad.

You must have been mad.

He mustn’t have enough.

He mustn’t have had enough.

“Must” as Simple Modal

Imploring:

You must answer all the questions.

Please, don’t!

You mustn’t throw litter on the floor.

Admonition:

Must you smoke at the table!

“Must” as an Auxiliary

If he loses the elections, he must call elections.

“Must” as a Defective/Substitute

I must buy some toothpaste.

Endogenous Obligation:

We must wait until Tom arrives.

Past:

I had to buy some toothpaste.

We had to wait until Tom arrived.

“Can’t” as True Modal

She can’t work so much.

She can’t have worked so much.

“Can’t” as Simple Modal

Admonition:

Can’t you be quiet for a minute!

You can’t be serious!

“Can’t” as an Auxiliary

If you can’t speak English, you can’t apply for the job.

“Can’t” as a Defective/Substitute

I can’t understand it.

I can’t swim.

I can’t drive today.

I can’t see it.

“Needn’t” as True Modal

You needn’t use such bad language.

You needn’t have used such bad language.

“Needn’t” as Simple Modal

Admonition:

Ugh! What a horrible smell! Need you smoke so much!

“Needn’t” as an Auxiliary

If you are over sixty, you needn’t pay the full fare.

“Needn’t” as a Defective/Substitute

I don’t need to go = I needn’t go.

“’d rather” as True Modal

I’d rather stay here.

I’d rather have stayed here.

“’d rather” as an Auxiliary

Present Subjunctive:

I’d rather you wore something more formal.

Past Subjunctive:

I’d rather you had worn something more formal.