U8. Past Modals

PASTMODALS

WHAT IS THE DIFFERENCE BETWEEN MODAL AND AUXILIARY VERBS?

Auxiliary verbs add grammatical or functional meaning to the clauses in which they are used. They can be used to express aspect, voice, modality, tense, etc. For example, I have read this book so many times. “Have” is an auxiliary, which helps express the perfect aspect.

Modal verbs also fall in the category of auxiliary verbs. But they indicate the modality in a clause. You use them to express certainty, ability, willingness, necessity, permission, obligation, advice, and possibility. For instance: Mary might come tomorrow. “Might” is a modal verb here, and it shows the likelihood of a certain action.

NB: All modal verbs are auxiliaries, but not all auxiliaries are modal verbs.

WHAT ARE THE 5 MAIN TYPES OF MODALS?

Modals denoting ability: can and could.

I can speak four languages.

Modals expressing permission: can and may.

May I open the window?

Modals for likelihood: will, might, may, can, and could.

It may rain today.

WHAT ARE THE 5 MAIN TYPES OF MODALS?

Modals denoting obligation: must and have to.

You must do your homework regularly.

Modals for giving advice: should.

I think you should stop smoking.

HOW DO YOU USE MODALS CORRECTLY?

• Modal verbs always come first in a verb phrase.

I can swim very well.

• Modal verbs are followed by bare infinitives.

You should be more careful next time.

• You can’t add “-s”, “-ed”, or “-ing” to modals:

Mary must work hard today.

• Modal verbs form their negative and interrogative like other auxiliaries:

I can't dive.

We can use modal verbs for deduction – guessing if something is true using the available information. The modal verb we choose shows how certain we are about the possibility.

Could have, would have, and should have are sometimes called “modals of lost opportunities.” They work like a grammatical time machine. The simple past just tells what happened. Past modals tell what could have, would have, and should have happened.

Would have

Would have is a bit more difficult because it has two common structures. The first is with but. I would have A, but I had to B. Use this structure to show that you wanted to do something in the past, but you could not.

I would have called, but there was no phone service. I would have loaned you the money, but I didn’t have any.

Would have also forms the result clause of a past unreal conditional. For example: If I had known they were vegetarians, I would have made a salad.

You can always reverse conditional sentences. If would have comes first, there is no comma. I would have made a salad if I had known they were vegetarians.

Should have

Should have means that something did not happen, but we wish it had happened. We use should have to talk about past mistakes. A worried mother might say:“I was so worried about you. You should have called!”

Should have is common in apologies. For example:I’m sorry that I’m late for work. I should have woken up earlier.

190+

countries

​Could have

Could have means that something was possible in the past, but it did not happen. I could have gone directly to college, but I decided to travel for a year.

Native speakers often do not pronounce their past tense modals clearly. Could have been usually gets contracted to could’ve been or even coulda’ been.

Listen to Marlon Brando in the classic film “On the Waterfront.” Brando’s character, Terry Malloy, was once a promising young boxer. “You don’t understand. I coulda’ had class. I coulda’ been a contender. I could have been somebody—instead of a bum.”

Can't have / couldn't have

We use can't have and couldn't have + past participle when we think it's not possible that something happened. She can't have driven there. Her car keys are still here.

Might have / May have We can use might have or may have + past participle when we think it's possible that something happened. I think I might have left the air conditioning on. Please can you check?

Must have We use must have + past participle when we feel sure about what happened. The thief must have had a key. The door was locked and nothing was broken.