11、关系副词when与where、why、that
when 指时间 = in / at / on / during which
where指地点 = in / at / from / which
why指原因 = for which
当先行词为way、day、reason、time时，可用that作关系副词。（非正式场合）
I don’t like the way that / in which / he talks.
当time作先行词时，关系词可以省掉。
This is the first time I have given you a lesson in French.
12、必须注意的问题
（1）关系词作主语时，从句中谓语的数。
（2）注意区别定语从句与强调句。
①定语从句中关系词作从句成分，复合句。
②强调it无意义，that / who不是引导词。
③强调it is / was和that / who后如果句子意思讲得通则是强调句，讲不通则不是。
It is the museum that/which we visited last year.(定语从句)
It was in the hotel that we stayed last night.（强调句）
（3）定语从句与同位语从句的区别。
①定语从句引导词被称为关系词，that充当主语、宾语、表语。有时可省略。
②同位语从句引导词被叫做连词，that不能充当任何成分，不可省。
Word came that their army was defeated.(同位语)
We expressed to them our wish that was the same as their.(定语)
（4）关系词在从句中省略的情况。
①关系词作宾语，前无介词时。
②关系词作表语。