首先就是一些情态动词等,如can,could,may,might,must,need,should,will,would,oughtto等
然后就是一些需要识记的短语:
最好做某事hadbetterdosth.
帮助某人做某事helpsb.(to)dosth.
让某人做某事letsb.dosth.
使某人做某事makesb.dosth.
为什么不做某事whynotdosth.
看见某人正在做某事see/watch/notice/observesb.dosth.
听见某人做了某事hearsb.dosth.
宁愿做某事wouldratherdosth