英語有一個 grammar 問題,筆者要一再重申,因為太多人不清楚而經常以為別人犯錯。先看以下這句:
Her parents
demand that she go home before midnight.
很多人見到上句都會忍不住把 go 改為 goes,因為前面是 she 嘛,問題是 that 後面是一個子句,受動詞 demand 所牽制,而事實上這句是正確無誤的。
英語有些動詞主要表達想法、建議、勸告、命令、要求、請求等,例如 advise, command, demand, insist, propose, recommend, request, suggest, urge 等,當這些動詞後接
that-clause,句子便處於一種叫 subjunctive
mood 的狀態,中文叫「虛擬語氣」,意思即是 that-clause 內所述的事是假設或想像的,現實中還未出現或進行,故此子句中的動詞不受 tense 限制,而需要以 infinitive 的形式出現,所以上句的 she go home 不用改為 she goes home。
基本上,無論主動詞是現在式或過去式,that-clause 內的動詞都是同樣的 subjunctive,例如:
I suggest that
he study law at university.
I suggested that
he study law at university.
分別只在於你 suggest 的時態有變,但所 suggest 的事情並沒有變。
如果 that-clause 內的動詞是 is/are/was/were,就要用 be (infinitive form),例如:
They insist that
he be innocent.
如果是否定式,直接在動詞前加 not,例如:
She requested that they not be invited to join the club.
She requested that they not be invited to join the club.
有時如果你怕別人誤會自己寫錯英語,可以加 should:
The doctor recommended that he should stop doing vigorous exercise.
= The doctor recommended that he stop doing vigorous exercise.
The doctor recommended that he should stop doing vigorous exercise.
= The doctor recommended that he stop doing vigorous exercise.