This often comes as a setback for students of Russian: of (almost) every Russian verb there are two. Which do mean approximately the same thing, but express very different things. So you need to know both, and of both learn the conjugations.

With “with,” you immediately have the key word for the instrumental case. With a discount, with Katya, with respect, by hand: all instrumental case or творительный падеж. You can do much more with this case; it’s truly a beautiful and useful tool.