I'm learning English grammar now for the first time, and I find it extremely confusing.
A verb is defined as
an action, an occurrence, or a state of being. Whether mental, physical, or mechanical, verbs always express activity.
If verbs are about a state of being, then why isn't "sad" a verb? Isn't it a state of being? Why is it any different from "recognized", which is a verb because it describes a cognitive state?