我哥哥是大学生。

Wǒ gēge shì dàxuéshēng.

My older brother is a college student.

我是大学生，我在北京学习。

Wǒ shì dàxuéshēng, wǒ zài Běijīng xuéxí.

I am a college student; I study in Beijing.

姐姐是大学生，她很忙。

Jiějie shì dàxuéshēng, tā hěn máng.

My older sister is a college student; she is very busy.