情态动词加have done表示过去 主语是单三时,have需要变为has吗?

2025-04-01 10:06:29
推荐回答(2个)
回答1:

先看情态动词+have
done
的用法结构:1.
must
+
have
done:用于肯定句,表示推测,意为“一定(已经)……”。
2.
can
+
have
done:用于否定句或疑问句,表示推测,意为“可能(已经)……”。
3.
could
+
have
done:可用于肯定句、否定句或疑问句,表示推测、责备或遗憾等,意为“可能……”、“本来可以……”、“本来应该……”等。
4.
should
[ought
to]
+
have
done:可用于肯定句、否定句或疑问句,表示责备或遗憾等,意为“本来应该……”。
5.
need
+
have
done:用于否定句或疑问句,用于否定时意为“本来不必”,用于疑问句时意为“有必要……吗”。
6.
may
+
have
done:用于肯定句或否定句,表示推测,意为“可能(已经)……”。
7.
might
+
have
done:用于肯定句或否定句,表示推测,意为“可能(已经)……(此时
might
可换为
may);另外还可以表示过来可能发生的事结果未发生,意为“本来会……”(此时
might
不能换为
may)。
情态动词+have
done
有反意问句,但变化时不看情态动词,看这些句子的时间时态决定,看看例子吧:1,He
must
have
been
to
Beijing,hasn't
he?
2,He
can't
have
gone
to
Shanghai
yesterday,did
he?

回答2:

1“can(could)
+
have
+
过去分词”的疑问或否定形式表示对过去发生的行为怀疑或不肯定。如:
he
cannot
have
been
to
that
town.
can
he
have
got
the
book?
2“may(might)
+
have
+
过去分词”表示对过去发生的行为的推测。如:
he
may
not
have
finished
the
work.
3“must
+
have
+
过去分词”的结构常用在肯定句中,表示对过去发生的行为的推测。它的否定或疑问式用can代替must。
he
must
have
been
to
shanghai.
4
need表示“需要”或“必须”,作情态动词时,仅用于否定句或疑问句中,在肯定句中一般用must,
have
to,
ought
to,或should代替。如:
you
needn’t
come
so
early.

need
i
finish
the
work
today?

yes,
you
must.
注意:needn't
+
不定式的完成式“表示本来不必做某事而实际上做了某事”。如:
you
needn't
have
waited
for
me.
“should
+
have
+
过去分词”结构一般表示义务,表示应该做到而实际上没有做到,并包含一种埋怨、责备的口气。如:
she
should
have
finished
it.
i
should
have
helped
her,
but
i
never
could.
you
should
have
started
earlier.