,The past tense is sometimes used in English to refer
to an unreal situation. So, although the verb tense is in
the past, we are actually talking about something that
didn't happen. This is often the case in conditional
sentences when we are talking about a hypothetical
situation that might exist now or at any time. We call
this use of the past tense "the unreal past".
, The unreal past is used after conditional words and
expressions like if, supposing, if only, what if; after the
verb to wish; and after the expression I'd rather.