I've come across a chart that explains Auxiliary. In "can" and "could" part, I don't know if there's any difference in meaning between (a) and (c) or (b) and (d).
Do they mean the same? Or is it just a matter of degree of certainty?
can... Impossibility (negative only)
(a) That can't be true! (Present / Future)
(b) That can't have been true! (Past)
could... Impossibility (negative only)
(c) That couldn't be true! (Present / Future)
(d) That couldn't have been true! (Past)
Thank you in advance.
(I may be late to respond, but I'd appreciate your help.)
Do they mean the same? Or is it just a matter of degree of certainty?
can... Impossibility (negative only)
(a) That can't be true! (Present / Future)
(b) That can't have been true! (Past)
could... Impossibility (negative only)
(c) That couldn't be true! (Present / Future)
(d) That couldn't have been true! (Past)
Thank you in advance.
(I may be late to respond, but I'd appreciate your help.)