7.5 Auxiliary Verbs

• Primary Auxiliaries
• Semi-Auxiliaries

Primary Auxiliaries

	Present Tense	Past Tense
be	am is are	was was were
do	do, does	did
have	have, has	had
shall	shall	should
will	will	would

否定式：在其后加 not， am not; do not; had not; would not ...

相关信息

本身没有词汇意义，不能单独作谓语，只能用来帮助主动词构成各种时态、语态、语气、否定式和疑问式

Semi-auxiliaries

类别	构成方法	疑问	否定
第一类	be + adj./v-ed/prep + to
第二类	appear/seem/chance/happen, etc. + to

相关信息

介于实义动词与助动词之间的结构。
本身具有词义，但又不能单独作谓语，必须和不定式连用构成复合谓语，才能表达完整词义

• In rapid speech, modals seem to disappear because they are ...
  -《You had better learn modals》