1. The next Olympic Games are in two years, by which time I will be a university student.
2. He came back eight months later, by which time the Japanese had decided to say yes.
有高手分析过,解释是 in two years 和 eight months later 分别在两个句子中作先行词表时间点,但是定语从句先行词可以是介词短语吗?另外,请问 by which time 能不能去掉 time?
你提到的分析是对的。受定语从句修饰的先行词通常应是名词或代词,但有时也可能是副词或起副词作用的介词短语。又如:
Let’s go inside where we can sit down. 咱们进去找个地方坐下。
Let’s cross over here where it’s shallow. 我们从这里过去吧,这里比较浅。
Why don’t we go upstairs where it’s more private? 我们为什么不到楼上去呢?那里清静些。
另外,你问到能否把 by which time 的 time 去掉或改为 when——回答是:不能。否则,意思不明确。