第1个回答 2011-04-25
Should,shouldn't,would,had better,must,mustn't,shall,may,might
一般现在时,主语+情态动词(often,usually,never,seldom,always,every day.....)+动词原形
将来时:主语+will+v原形+其它 或 主语+be going to +v原形
过去式:主语+was/were+其它 或 主语+动词的过去式+其它正在进行时:主语+be(am,is,are)+V-ing+其它
第2个回答 2011-04-26
情态动词无人称和数的变化, 情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加 "not"。如 must,can(could),may(might);need,dare ;have(had,has) to,used to 等后面都+v原形。
第3个回答 2011-05-13
must,can(could),may(might);need,dare ;have(had,has) to,used to
第4个回答 2011-04-27
will do
be going to do
used to do(过去常常)
must do/mustn`t do
have to do/don`t have to do
It`s adj for sb. to do sth
can/can`t
shall/should及否定形式
may/might及否定形式
often seldom never always usually sometimes
like to do
need to do
be supposed to do/be expected to do