A linking verb connects the subject with some more information about the subject.
These are examples of some of the main linking verbs:
1. Be: I am extremely tired this evening.
2. Look: My hair looks a mess today.
3. Feel: My head feels fuzzy.
4. Taste: This glass of Scotch tastes good.
5. Smell: This pizza smells rather strange.
6. Sound: My neighbours sound very angry.
7. Seem: They seem determined to keep me awake tonight.
Here are some others; if you want to try to make some sentences with them, I'll check them for you:
Appear; Get; Become; Grow; Stay; Keep; Turn; Prove; Go; Remain; Resemble; Run; Lie.
All the best,
PS: Have you tried the "Reference" link, at the top of the page? If you search on "Linking verbs", you'll find some more information.