 Now, let's have a look at the past continuous tense. This tense is used to indicate that a certain action was in progress at a particular time in the past. We form the positive form by using our subjects, the auxiliary verb to be, plus the verb plus ing, also known as the present participle. So it results in sentences such as, he was cooking last night, or we were cooking last night. In order to form the negative sentence for the past continuous, we add the word not in between the past form of the auxiliary verb to be, and our main verb, which here is cooking. So of course we have, he was not cooking last night, and we were not cooking last night. In order to form the question form of the past continuous tense, again we're going to invert a subject and the auxiliary verb. So we start our question with was, or were, depending on our subjects, and we keep our present participle form of the verb, which is our main verb in the question. So was he cooking last night, or were you cooking last night? The usage for the past continuous tense is expressing actions in progress at a time in the past. So one example could be, I was cooking at 6pm last night. I was cooking. It was an action that began, occurred, and finished at a particular point in time in the past, 6pm last night. Now, I could also say, I was cooking when you called me. It's the continuation of an action that happened at a particular time. That particular time needs to be conjugated into the past simple tense, as it wasn't continuing, rather the cooking was continuing.