Question

He is ( )to go to school . A.old enough

He is ( )to go to school .
A.old enough B.enough old
C.too year D.enough too

做出选择题后，请解释一下原因

Answer 1

选择A
因为 enough作副词用时，意为“充分地；足够地”，通常要把它放在所修饰的形容词、副词或动词的后面，常与不定式或介词for连用
He is not old enough to go to school. 他年龄太小，不能去上学。

例句

1. You don't practise enough at the piano. 你钢琴弹奏练习得不够。

2. Is the river deep enough for swimming? 河水够深来游泳吗？

Answer 2

答案选A，形容词+enough=It's +形容词+to

Answer 3

选A enough 修饰形容词时后置

Answer 4

选A，enough修饰形容词时enough后置