did/were用于对现在的虚拟
If
I
had
a
lot
of
money,
I
would
buy
a
car.如果我有钱,我就买辆车
If
I
were
you,
I
wouldn't
do
that.如果我是你,就不会那么做的。
were
to
do/should
do用于对将来时态的虚拟,都可以用,都是虚拟,意思上略有差别,should可能多用“万一、竟然”这个意思
If
he
were
to
come,
what
would
you
do?如果他来,你怎么办?
If
it
should
rain,
take
an
ambrella.万一下雨,带把伞
没有区别,if
引导虚拟语气有与将来事实相反有三种情况:从句1)
if
+
should
+
do(动词原型);
2)
if
+
were
to
+do(动词原型);
3)
if
+
did(过去式);
主句
would/could/should/might
+
do(动词原型)
三种都一样,任选一种就可以。