TESOL Courses Philadelphia

I learned from this unit that the past tense has four categories: simple past, past perfect, past continuous, and past perfect continuous. The very important thing I learned is that forming the past continuous uses the irregular past form of the verb \"be\" which is \"was/were\". The other two tenses of past perfect and past perfect continuous use the past form of the verb \"have\" which is \"had\". Past participles are formed using \"had\" plus regular verb 'ed'. However, there are many irregular past participles that do not follow the rule \"add ed or d to the base\" and that there are nor rules, rather they just have to be memorized by students. Also any tense with the word \"continuous\" must have at least one auxiliary helping verb plus a verb ending in \"ing\". The past perfect continuous tense is the only tense that must have two auxiliary helping verbs, \"had\" + \"been\" + ____ing\". Past simple and past continuous tenses use \"was/were\" + _____ing, while the past perfect and past perfect continuous use \"had\"/\"had been\" + ______ing.