Yes, it can be used with any verb. However, it's only used if you want to emphasize that something is ongoing or happening right now: Ich bin gerade beschäftigt = I'm busy right now. In many cases, you'd translate the continous form just as a simple tense, without "gerade". Just like there are two kinds of passive in German (Zustandspassiv/sein, Vorgangspassiv/werden), and you have to translate those using one kind of passive in English. There are similar expressions like "im Moment" or "gerade jetzt", but they each have their specific meaning and specific way of usage. There's also the colloquial form "am/beim + infinitive used as noun", and you can add "gerade" for emphasis, too: Ich bin (gerade) am Lesen, stör mich bitte nicht. Ich bin (gerade) beim Kochen, ich habe jetzt keine Zeit. Don't use this in written German.