「現在事實相反」的假設語氣

If+主詞+ were…, 主詞+ would/should  +原形V

     過去式動詞….，  could/might

If I were you, I would tell the truth.

假如我是你，我會說實話。

補充: 在此句型中的「if子句」之動詞須用「過去式」,而be動詞不論人稱一律用were

「過去事實相反」的假設語氣

if+主詞+had+P.P….,主詞+ would/should +have+P.P

If I had had enough time, I would have gone with you.

假如當時我有足夠的時間，我會和你去。

補充: 此句型的主要子句經常有：now, today, this year…..等字。

例句：假如以前好好讀書的話，現在就可以回答這問題了。

　 If I had studies hard before, I could answer the question now.