I saw these two following sentences in a text book, and I have some questions about them.<br/><br/>1) Would you have told me the answer if you knew it?<br/><br/>Shouldn't it be:<br/><br/>Would you have told me the answer if you had known it?<br/><br/>2) He would have worked if he weren't tired.<br/><br/>Shouldn't it be:<br/><br/>He would have worked if you had not been tired?<br/><br/>Is this some kind of informal way to express the type III hypthetical "if"?<br/><br/>Thank you.