Affirmative/negative sentences with 是
S + 是 + N / S + 不是 + NUse '是' (shì) to affirm identity, occupation, or relationship. Use '不是' (bú shì) to negate. This is the most basic structure for introducing yourself or others.
那个女人是我妈妈。
That woman is my mother.
他不是老人。
He is not an old man.