在日常生活中，我们常常需要提醒他人注意某些事情，这时就可以使用“warn sb to do sth”这一结构来表达警告或提醒的意义。以下是一些实用的例句，帮助大家更好地掌握这个语法点：

1. 父母经常告诫孩子不要玩火。

- Parents often warn their children not to play with fire.

2. 老师提醒学生们考试前要复习好功课。

- The teacher warns the students to review their lessons before the exam.

3. 请记得提醒他按时提交报告。

- Please remember to warn him to submit the report on time.

4. 在河边玩耍时，我们要小心别掉进水里。

- When playing by the river, we should be careful not to fall into the water.

5. 出门前，妈妈总是叮嘱我带伞以防下雨。

- Before going out, my mother always warns me to take an umbrella in case it rains.

通过以上句子可以看出，“warn sb to do sth”的用法非常灵活，适用于多种场景。希望大家能够多加练习，逐渐熟悉并运用到自己的实际交流中去。