P implies Q, how to read in english

Not P Or Q. This version you want?

Translating your example:

Distributivity

Ka[Z] : ‘A knows Z is true’

Ka[(X->Y)] -> (Ka[X] -> Ka[Y])

If A knows that from X follows Y, then from A knowing that X is true it follows that A knows that Y is true.

Perhaps it helps you to understand that if you imagine a small example from the real world:

Fire implies Heat

That means if you have fire, there must be heat. If there is no fire, there can be heat, due to other effects (e.g. sun is shining :) ), but there could as well be no heat.

If you have fire but no heat, somethings wrong. The implication is false then.

"P implies Q" is equivalent to "if P, then Q".