What is modus ponens?

Modus Ponens is very simple.

lets say you have this example

If today is Monday, then tomorrow is Tuesday.

Today is Monday

Therefore tomorrow is Tuesday.

That is a valid argument because of modus ponens

If the premise(if today is monday) is true then you must accept the conclusion(Then Tommorow is Tuesday) as true also.

Another example

If P, then Q

P

Therefore Q