Formal:
* 我是一名学生。 (Wǒ shì yī míng xuéshēng.) - This is the most common and formal way to say "I am a student."
* 我是学生。 (Wǒ shì xuéshēng.) - This is slightly less formal than the previous option, but still widely used.
Informal:
* 我念书。 (Wǒ niàn shū.) - This literally means "I read books" but is commonly used to mean "I'm a student."
* 我上学。 (Wǒ shàng xué.) - This means "I go to school" and can be used informally to indicate being a student.
Using a specific grade level:
* 我是一名高中生。 (Wǒ shì yī míng gāozhōngshēng.) - I am a high school student.
* 我是一名大学生。 (Wǒ shì yī míng dàxuéshēng.) - I am a university student.
You can also say "I am studying..." followed by your specific area of study:
* 我正在学习中文。 (Wǒ zhèngzài xuéxí zhōngwén.) - I am studying Chinese.
The best way to say "I am a student" in Chinese will depend on the specific situation and who you are talking to.