So, if Q is false P can't be true.

如果Q是假的，P也不会是真的。

Because necessary condition for P and Q being true if P and Q are true. Sorry. It is. You all knew that immediately.

因为P和Q为真的必要条件，如果P和Q为真，不是，你们立刻知道了。

But if I then say Not P and say is this true?

但是如果我说非p为真呢？