什么是 “keep sb on doing”？
实际上，标准英语中并没有“keep sb on doing”这一固定搭配。常见的正确表达是：
- keep sb doing sth：让某人持续做某事
- keep on doing sth：不停地做某事（主语通常是自己）
因此，“keep sb on doing” 很可能是对上述两个结构的混淆。
正确用法示例
1. keep + 宾语 + doing
- The teacher kept the students practicing grammar exercises.
- Don’t keep him waiting outside.
2. keep on + doing（无宾语）
- He kept on talking even after the meeting ended.
- She kept on studying despite being tired.
常见错误与纠正
❌ 错误：He kept me on working late.
✅ 正确：He kept me working late. 或 I kept on working late.
“on” 在 “keep on doing” 中是副词，不能插入宾语之后。
小结
记住：
- 如果有宾语（sb），用 keep sb doing。
- 如果强调动作持续不断且主语自己执行，用 keep on doing。
- 不要将两者混合成 “keep sb on doing”，这是不符合英语习惯的表达。