1. 强调nothing,由nothing引导的句子前部分要倒装吗

你好。如果nothing做主语就不要倒装,如:
Nothing that you did ever pleased Mary.
除此以外都要倒装
1 She has bought nothing for me--------Nothing has she bought for me.
2 They needed nothing from him--------Nothing did they need from him.

2. 定语从句中前有nothing用什么引导

用that引导
如果nothing是先行词而且定语从句为限制性定语从句,那么定语从句用that引导,而且只能用that
但如果nothing不是先行词,那么引导的连词由先行词确定;如果定语从句是非限制性定语从句且先行词是nothing,那么只能用which做连词引导
当限制性定语从句的先行词为nothing,anything,all,none,few等时,定语从句的连词只能用that引导
如
I have nothing that can be read.
我没有什么可读的。
I have nothing,which has puzzled me a lot.
我一无所有,这个问题让我一直很困惑。
前者是限制性定语从句,连词只能用that引导;
但后者是非限制性定语从句,虽然前面也有nothing,但从句不再修饰nothing而是修饰整个主句,所以只能用which引导

3. that引导的句子都是从句吗

that既可作关系代词,又可作指示代词,用法很多,很多人都拿不准。