Questions & Answers about Come reagisci?
In Italian, come is very often a question word meaning how.
So in Come reagisci?, come means how, not the verb to come.
- Come stai? = How are you?
- Come funziona? = How does it work?
- Come reagisci? = How do you react?
Italian come can also appear in other contexts, but in a question like this, how is the natural interpretation.