用情态动词被动语态造的肯定句,否定句,一般疑问句

Question

如题所述

Answer 1

用于表示“需要，必要”之意。做情态动词时，仅用于否定句和疑问句，只有现在时，过去式要用needn't
have，疑问式用need+人称?,否定式用need
not(即needn't），
1．—need
we
leave
soon?
—yes,
you
must.(no,
you
needn't)
2．you
needn't
have
hurried.
(=it
was
not
necessary
for
you
to
hurry，but
you
did).你当时不必这么匆忙。
3.he
needs
to
see
a
doctor.(need
to
do)