You can tell when a third-person point of view is used when the narrator does not use personal pronouns.
First-person point of view uses personal pronouns, such as: "I went to the grocery store and I bought some grapes." First-person makes it seem as though the story is written from your viewpoint and you are the character.
Third-person point of view does not use personal pronouns, such as: "She went to the grocery store and she bought some grapes." Third person is written so that it feels as though you are reading about another person.\
