记

记

"记" means "to remember," "record," or "note."

In this sentence, 记 is used as 'note down' or 'record', shown in the verb phrase 记下.

请你记下我的电话号码。

Please write down my phone number.

Here, 记 implies 'to take note of', indicating the action of paying attention to and remembering details.

你上课要记好老师讲的内容。

You should take careful notes of what the teacher says in class.

Here, 记 is used in the sense of 'recall' or 'remember', embedded in the compound verb 记得.

我记得今天是你妹妹的生日。

I remember that today is your sister's birthday.