How to Use 是 (shì) in Chinese
Use 是 to identify someone or something, and learn why it does not fit every English "is."
Use 是 to identify
是 connects a subject with a noun or noun phrase.
Example
我是学生。
I am a student.
Example
她是我姐姐。
She is my older sister.
Do not translate every "is" as 是
In a simple description with an adjective, Chinese often uses 很 rather than 是.
Example
他很高。
He is tall.
In a neutral description like this, 很 does not necessarily emphasize "very."
Compare
他是老师。 means "He is a teacher."
Example
他是老师。
He is a teacher.
他很高。 means "He is tall."
For your first sentences, remember: 是 works well for identifying people and things; adjective descriptions often use another pattern.