定义 / 说明
在高级用法中，分词常出现在连接词或介词后，如 after, before, when, while, without, instead of, in spite of。这种结构可使句子更短、更流畅，也常更正式。尤其适合把动作表达为一般活动而非完整从句。介词后英语通常用 -ing，而不是不定式。掌握这些模式可提升书面衔接与口语灵活度。
关键规则
- 大多数介词后用 verb-ing：without saying, after leaving, before starting。
- when/while 后可用完整从句或 -ing 形式：When leaving, lock the door.
- 固定模式：in spite of + -ing, instead of + -ing, by + -ing。
- 介词后不要直接用 to + verb。
- 常见于说明文、正式写作、简洁叙述。
例句
- Before leaving, lock the door. - 离开前把门锁好。
- In spite of being tired, she stayed. - 尽管很累，她还是留下了。
- He solved the problem by asking for help. - 他通过求助解决了问题。
- After reading the email, I called her. - 读完邮件后我给她打了电话。
- They left without saying goodbye. - 他们没道别就离开了。
常见错误
- ❌ Before to leave, lock the door. -> ✅ Before leaving, lock the door.
- ❌ In spite of be tired, she stayed. -> ✅ In spite of being tired, she stayed.
- ❌ He improved by to practise every day. -> ✅ He improved by practising every day.