MODALS FOR SPECULATIONS ANDINFERENCES ABOUT PAST SITUATIONS
MODALS FOR SPECULATIONS AND INFERENCES ABOUT PAST SITUATIONSWhen we make MUSTdeductions or MIGHT / MIGHT NOTinferences about past (MIGHTNT)situations, we can usethe same modals we MAY / MAY NOTused for speculations COULD / COULD NOTabout the present, with (COULDNT)the same meaning: CANT•
The difference is in the structure: PRESENT Modal + Base form of the verb PAST MODAL + HAVE + PAST PARTICIPLE
PRESENTAmelia can’t be alive (now). She disappeared in 1937. PASTAmelia’s plane might have had technical problems.
Remember: To make deductions or inferences in the past use:Must or Mustn’t + Have + When you have evidence Past Participle Can’t + Have + Past When something is unlikely Participle to have happened May (may not / Might(mightn’t) / Could + Have + When you are not so sure Past Participle about something
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 somepractice exercise about these kinds of modals.