主系表=主语+系动词+表语。主系表例句有：1.She is really my mother. 2.She is my aunt's friend. 3.She is very friendly. 4.She is very strict 5.She is an artist.
1.I am a middle school student.
2.I am from China.
3.I am fourteen years old.
4.I am a fourteen-year-old girl.
5.I am very outgoing.
6.I am happy everyday.
7.I am interested in English.
8.I am proud of my parents.
