ability
1. ability指体力或智力，后面通常接不定式，很少接of和动名词，如通常说ability to do it, ability to lift a great stone和ability to write correct English，很少说ability of doing it等，但可以说reading ability, writing ability, driving (驾驶) ability等，也可以说his ability in reading and writing, his ability in drawing等。
2. 单独用ability，除了可以从上下文看出指体力者以外，都指智力，如下面的ability都指智力：
- man of ability（有才的人），great ability（大才），
- in point of ability（就才能讲），He lacks ability. （他缺少才能。）
复数形式abilities只指智力，不指体力，如his abilities, manifold abilities 等都指智力。
3. ability to do it, the ability to do it, an ability to do it和his（或your等）ability to do it都可以说，第一种形式最不普通。
