How can you identify a verb/verb phrase, and how can you tell if it is present, past, future, pres. perf., past perf., future perf.?
For action verbs, you can usually identify the verb in a clause or sentence by asking yourself what someone/something is doing. What is the action?
For example, if you ask that question about this sentence -- John hit the baseball -- you should clearly identify "hit" -- it's the action. Nothing else in that sentence is something that anyone or anything could do.
Sometimes, though, there will be linking verbs instead of action verbs.
John hit the baseball. <~~"hit" is the action verb
John is my brother. <~~ "is" is the verb, but there's no action; simply being. The verb "is" is a link between "John" and "brother" and it's rather like an equals sign in a math equation.
Here are some webpages that are LOADED with information. Be sure to take the time to go through them completely:
http://www.englishpage.com/verbpage/types.html
and
http://www.englishpage.com/verbpage/verbtenseintro.html