Question

在什么情况下定语从句中不能用that

同上

Answer 1

先行词表示物时，关系代词只能用that而不用which的情况如下：
1) 不定代词（all, much, something, everything, anything, nothing, none, the one）作先行词时；
e.g. There is nothing that can be done by us.
2) 先行词被only, any, few, little, no, all, one of, just, very, much等词修饰时；
e.g. The only thing that I can do is to wait. The pen is the only thing that I have.
3) 先行词是序数词或被序数词修饰时；
e.g. This is the first time that I visit Beijing.
4) 先行词是形容词最高级或被形容词最高级修饰时；
e.g. The most important thing that I did is being a good father.
5) 先行词既有人又有物时；先行词既有时间又有地点时；
e.g. The police are looking over the man and his dog that were killed by the tiger.
The time and the place that we will hold the meeting has not been decided yet.
6) 先行词是数词时；
e.g. I bought 3 pens yesterday, now you can find 2 that have broken.
7) 如有两个从句，其中一个关系代词已用which，另一个关系代词宜用that。
e.g. He built a factory which produced things that had never been seen before.

在非限定性定语从句中，不能用that，而用who, whom代表人，用which代表事物.

非限定性定语从句：非限定性定语从句的作用是对所修饰的成分作进一步说明，通常和主句间用逗号隔开，将从句拿掉后其他部分仍可成立

Answer 2

主要是非限定性定语从句
即用逗号隔开的句子
that不能引导某些先行词
推荐还是使用wh-的引导词

Answer 3

that是定名词的从句先行引导词；定其他成份的定语从句都不能用that，要用where when等

Answer 4

一、在非限制性定语从句中，不可以用that【说得简单点就是逗号后，如果填定语从句引导词的话不可以用that
eg：Peter,
whom
you
met
in
London,
is
now
back
in
Paris.
彼得现在回巴黎了，你在伦敦见过他。
【这里只能用whom，不能用that
二、再有就是，介词前置的情况下不能用that，也就是介词后的引导词不能用that
eg：Sandstorm
is
a
serious
problem
that
we
‘re
faced
with.
沙尘暴是我们正面临的一个严重的问题。
【这里可以用that
但如果介词前置，Sandstorm
is
a
serious
problem
with
which
we
‘re
faced.
那么，引导词就不能用that了

Answer 5

1.非限制性定语从句
2.关系代词前面有介词