例句：
1、Our son's having problems with his reading and writing.
我们儿子在读写方面有困难。
2、I've never been a great one for writing letters.
我向来不喜欢写信。
3、She hasn't written ─ not that she said she would.
她还没写信来——倒不是她说过她要写。
4、This expression is used mainly in speech, not in writing.
这种表达主要用于口语，而不是书面语。