你指的是我吗？

Nǐ zhǐ de shì wǒ ma?

Are you referring to me?

你可以指出照片中哪一个是他妈妈吗？

Nǐ kěyǐ zhǐchū zhàopiàn zhōng nǎ yí gè shì tā māma ma?

Can you point out which person in the picture is his mother?

你说的“他”是指谁？

Nǐ shuō de “tā” shì zhǐ shéi?

The “he” you mentioned refers to whom?