题目内容：

all i have to do is learn english.为什么不是all i have to do is learning english

优质解答

此句采用了不定式的省略语法：如果主语中含有行为动词do及其变化形式did/does/done等时,则做表语的不定式符号to一般省略.完整句子为：All I have to do is (to) learn English.该句表语to learn English为不定式,前...