If you are caught driving drunk, your license privilege _____ .
(A) forfeits
(B) forfeited
(C) will be forfeited
(D) would have forfeited

假設語氣【口訣：與現在事實相反→用過去式 ; 與過去事實→用過去完成式 ;與未來事實相反→以現在式助動詞代替未來式。】

(1)與現在事實相反→if子句用【過去式】

If + S + V-pt (過去式), S + [would / should / might / could] + V (原形)

If I were you, I would tell the truth.假如我是你，我就會說實話 。

(2)與過去事實相反→if 子句用【過去完成式】

If + S + had + p.p., S + [would / should / might / could] + have + p.p.

If I had finished my homework, I would have cooked for you.假如我把功課做好的話，我就會幫你煮飯。

(3)與未來事實相反→if子句用【現在式助動詞】代替未來式

If + S + should + V(原形), S + [shall, will, can, may（可能性高）或should, would, could, might（可能性低）] + V (原形)

If it should rain, I will stay home.萬一下雨，我就會待在家裡。（可能下雨，果真如此，我會待在家裡）

1. forfeit [ˋfɔr͵fɪt]（因犯罪、失職、違約等）喪失（權利、名譽、生命等）He has forfeited the right to be the leader of this nation.   他喪失了作為這個國家領導的權利。