In Verbs^x, Negations^x, Whom^x

Here are some examples The main point is to explain the correct answer The sentences are little-bit childisch ;they are some modified sentences. I am afraid that my explanations seems to be a little childisch, too. So please help me how to turn it into the right explanation. Mary was real...

Do existed in Old English more than a thousand years ago as a regular verb and meant to cause . It is impossible to say who introduced it to English. It's use as an auxiliary in questions and negations was established in Shakespeare's day when it was correct to say both I know not him...