Use Yes/No questions when: This type of question is used to corroborate something that we think is true. Ex: Isn't oscar excited for his birthday?? (Yes, he is) Didn't you exercise last week? (Yes, I trained very hard) It is used when we want someone to agree with us. Ex: Don't you know your blog assignment is due today? (No, I had forgotten) Wasn't your dance wrong? (No, that is the choreography) To express surprise. Ex: Aren't you going to English class tomorrow? (Not really. I have a very important meeting, I'm sorry) Haven't you eaten anything today? (Yes, but just a little) The grammatical tenses of each verb Verb to be ( Isn't/Aren't ): simple present Verb to be ( Wasn't/Weren't ): simple past Auxiliary Don't/Doesn't : simple present Auxiliary Didn't : simple past Auxiliary Hasn't/Haven't : present perfect