modals

[tim_yhen@yahoo.com]

hi!

I just want to ask if we can use modals interchangebly? For example, can, could and must which suggest possibilty.

I hope you can help.

[riverkid]

hi!

I just want to ask if we can use modals interchangebly? For example, can, could and must which suggest possibilty.

I hope you can help.

Not generally, Tim. Each modal has its own area of meaning within two wider subsets; epistemic modal meanings which describe levels of certainty and deontic modal meanings which describe social uses of modals such as necessity, obligation, advice, permission, etc.

There are times when the situation is such either of two modals "adjacent" modals could/can be used. There, I've just done it with 'can/could'.