在need,require,want后接-ing形式，表示被动意义，也可接不定式，但要用被动形式，如：Your handwr iting needs improving(tobe improved). hate,love,like接不定式表示特定的未来事件，接动名词表示目前 正在进行的活动或一般的行为。
在下列情况下，一般要用不定式：
①hate,like,love前有would(should)时，如：I`d like to have a cup of coffee.
②当谓语动词begin,continue,start等是进行式时，如：Thestudents are starting to work on the di fficult maths problem.
③begin,continue,start与know,understand等状态动词连用时，如：I soon began to understand what
was happening.
⒋advise,allow,encourage,forbid,permit等动词后接动名词作宾语，或带不定式作宾语补足语。如：
Our teachers don`t permit our swimming in the lake.
Our teachers don`t permit us to swim in the lake.
⒌部分动词后接不定式或动名词时，意义差别较大，应根据句子语境选择使用。
①forget,remember,regret后接不定式，表示现在或未来的动作，接动名词表示动作已经发生。如：
Don`t forget fo post the letter for me.
Have you forgotten meeting her in Beijing Airport?
Remember to close the windows before you leave.
I remember writing him a letter a year ago.
We regret to tell you that all of you are not invited toattend the meeting.
They regretted ordering these books from abroad.
②mean to do 打算做某事
doing 意味着……
I meant to catch up with the early bus.
This means wasting a lot of money.
③try to do 设法尽力做某事
doing 试着做某事
You should try to overcome your shortcomings.
Try working out the physics problem in another way.
④stop to do 停下一件事去做另一件事（不定式作目的状语）
doing 停止做某事
On the way to the airport,I stopped to buy a paper.
You`d better stop arguing and do as you are told.
⑤can`t help doing 禁不住……
to do不能帮助干……
They couldn`t help jumping up at the news.