MODALS FOR SPECULATIONS AND INFERENCES ABOUT PAST SITUATIONS

MODALS FOR SPECULATIONS AND INFERENCES ABOUT PAST SITUATIONS

When we make deductions or inferences about past situations, we can use the same modals we used for speculations about the present, with the same meaning:

MUSTMIGHT / MIGHT NOT

(MIGHTN'T)MAY / MAY NOT

COULD / COULD NOT (COULDN'T)

CAN'T

The difference is in the structure:

Modal + Base form of the verb

PRESENT

PAST MODAL + HAVE + PAST PARTICIPLE

PRESENT

Amelia can’t be alive (now). She disappeared in 1937.

PAST

Amelia’s plane might have had technical problems.

When you have evidence

When something is unlikely to have happened

When you are not so sure about something

Remember:To make deductions or inferences in the past

use:

Must or Mustn’t + Have + Past Participle

Can’t + Have + Past Participle

May (may not / Might (mightn’t) / Could + Have +

Past Participle

Atlantis mustn’t have existed. There is no evidence about it .

The crew from Mary Celeste might have been abducted.

The drawing could have been made by extraterrestrials.

Now click on the link to do some practice exercise about these kinds of

modals.