all i have to do is to do sth
问题描述：
all i have to do is to do sth
all i had to do was to write a story and present it
为什么write不改为wrote,前后时态一致?
答
这里主要有两个语法现象:1.all I have to do is 的后面需要跟不定式,即to加上动词原型.这个原型不受前面的have的时态的影响,不管是have,had,will have,had had等等,后面的只能是is加不定式；也不受这个is的时态影响,...