All I want to do is save your life.

问题描述:

All I want to do is save your life.
请分析一下这句话的结构,特别是is与save

All是主语,同时是定语从句的先行词,后面的Iwant to do是定语从句.is是整句的谓语动词,save在这里其实是to save的省略,在口语中,往往把表语中的不定式的to省略.