use c'est in sentences it/he/she is + a/the/my... + thing/people when using If it/he/she is is followed by un/une/le/la - use c'est After rereading the lesson, the second phrase of your question is stated after the examples and is a further explanation of c'est. That being said, the second rule states: "2. Cases expressing opinions or simple statements (adjectives) about previously mentioned things, look at these rules: a - c'est for general, unspecific statements and opinions" I hope this helps.