先行词在定语从句和非定语从句里涉及.这两者区别明显, 定语从句先行词后没有逗号,非定语从句的先行词后有逗号. 定语从句知识: 先行词是人,且在从句里做主语,引导词用who或that.(不可省略) he has a girlfriend who sit in the corner. 先行词是人,且在从句里做宾语,引导词用whom.(可省略) 先行词是物,且在从句里做主语,引导词用which或that.(不可省略) 先行词是物,且在从句里做宾语,引导词用which或that.(可省略) 先行词是地点,引导词用where.(不可省略)