Examples
guò qù过去,wǒ我shì是zhōng xué shēng中学生,xiàn zài现在wǒ我shì是dà xué shēng大学生.
过去,我是中学生,现在我是大学生.
In the past, I was a middle school student. Now I am a college student.
他只不过是个普普通通的中学生，不算特别聪明。
He's just a normal junior high school student, not particularly intelligent.