I just have a question about a detail on indicative vs. subjunctive:
I know that one grammar rule is that the subjunctive tense is used in a sentence where the subject of the independent clause is different from the subject of the dependent clause. However, indicative is used with expressions that do not express any doubt (e.g. those that begin with "es cierto", "pienso","sé", etc.).
However, what if we had a sentence where both are used, like: "Pienso que tú ___ (pensar) cuidadosamente antes de contestar mi pregunta." Would we use the indicative "piensas" or the subjunctive "pienses" in this situation?
Also, this is a very silly example that doesn't make a whole lot of sense, so if anyone has other examples that could help clarify my question they would be appreciated.