先行词是什么

1、先行词指人时，引导词可用Who,Whom,及that,其中当引导词在句中作主语时用Who或that；当其充当宾语时用whom或that，在非正式宾语中也可用who，也可省略。
a That boy who/that broke the window is called Tom.
b The person to whom you just talked is Mr Li.
b 句可改为：The person(that/whom/who)you just talked to is Mr Li.

2、先行词指物时，引导词用that或which
a.They planted the trees which didn’t need much water.
b .The fish (which)we bought were not fresh.

3、先行词指时间时，引导词用When/on which或in which
a.I still remember the day when/on which I first came to Bei jing.
b.I'll never forget the year when/ on which we worked on the farm.

4、先行词指地点时，引导词用Where或in which
This is the house where/in which we lived last year.
或:This is the house that/which we lived in last year.

5、whose在定语从句中作定语时，可用来指人，也可以用来指物，如:
a.This is the boy whose mother died a month ago.
b.This is the house whose windows were broken.此句可改成：
This is the house the w