一. 限定 (不加逗點, 若無此限定形容詞子句,語意會不完整) VS. 非限定(加逗點, 唯一的那個人,是補述用法)
2. Diana, who I spoke to in the morning, is very interested in our project.
═ Diana, to whom I spoke in the morning, is very interested in our project.
3. I need a secretary who has a college degree and can speak fluent Spanish.
4. The painting (which) you bought at a high price last week is a fake.
2. Had I known your telephone number, I would have called you last night. (屬於”與過去事實相反”的假設)
※3. You might have been killed had the rescue team not arrived in time. (屬於”與過去事實相反”的假設)
4. Should the train be delayed, please let me know at once. (屬於”對未來不確定”強烈的假設) 解釋為: 萬一
Without / But for / + N(片), S + would/should... (看是現在或過去的假設),
If it were not for N(片), S + whould/should + V.. = (倒裝): Were it not for N(片), S + whould/should + V..
If it had not been for N(片), S + whould/should have +pp.. = (倒裝): Had it not for N(片), S + whould/should have +pp..
5. Had it not been for your help, I would not have been able to fix my bike. (屬於”與過去事實相反”的假設)