Question

主语＋be＋adj＋enough＋to do sth什么意思

Answer 1

主语＋be＋adj＋enough＋to do sth的意思，根据形容词的情况而定。
He is old enough to join the army.他到了参军的年龄。
He is old enough to go to school.他到了上学的年龄了。
He is careful enough to work out the problem.他很细心能解出了这道题。
We are strong enough to beat them.我们足够强大能打败他们。

Answer 2

足够…能够…
He is old enough to join the army.他已经到了参军的年龄了。

adj＋enough＋n（名词）
He wants a long enough holiday.他想要一个足够长的假期。

Answer 3

Be careful to do
做某事的时候要小心。
Be careful to across the street.
过马路时要小心。
Be +形容词+to do意思就是:做什么的时候要怎样。