陈述句的强调句

It was him that /who I saw on the street last night.  

虽然我知道这是强调句的固定公式，不过这应该和定语从句没什么关系吧？

【答】没关系。

not...until句型的强调句

普通句：He didn't go to bed until his wife came back.

强调句：It was not until his wife came back that he went to bed.

这个强调结构我没能理解，能分析一下吗？

【答】本句强调的成分，实际是“until 引导的时间状语”，而不要笼统地说这是强调not ... until 句型。

至于为何把not 提前一起强调，这属于“否定转移”。因为句中的谓语动词没有被否定，实际最后还是发生的，只是在until 之前没有发生。

这涉及否定句如何变“强调句”的问题。否定的重心实际落在了until 从句上面，而不是谓语动词上，这时，应将not置于被强调部分里面。所以，就出现了：

He didn't go to bed until his wife came back.

→ It was not until his wife came back that he went to bed.

He didn’t realize his mistake until the teacher had told him.

→ It wasn’t until the teacher had told him that he realized his mistake.