All I have to do is learn English. 中的learn是不定式吗?

All I have to do is learn English. 中的learn是不定式吗?
All I have to do is learn English. 中的learn是不定式吗?

All I have to do is learn English. 中的learn是不定式吗?
墒÷圆欢ㄊ椒?to .All I have to do is learn English.句中的主语是all I have to do,表语是(to)learn English.此句是主系表结构.如果把此句的all换作WHAT引导,更明了了!
如果把上述句子中的不定式作主语,把含有 do 的名词性分句作表语,该不定式符号 to 仍然可以省略.