Useful, convenient, interesting: adjectives are everywhere and unavoidable. So it is sensible, rewarding, fascinating, attractive, necessary, etc., to be able to use them in speech and writing. Two things are needed for that.

You quickly learn or might already know the ‘regular’ forms of the Russian personal pronouns (those in the nominative case). I = я, you = ты, he = он, she = она, it = оно, we = мы, you (formal/plural) = вы, and they = они. These words change depending on the case; however, there are many similarities within these changes.