Subject	Verb to be in the past tense	Verb to be in the present tense	Verb to be in the future tense
I	was	am	will be
You	were	are	will be
He / She / It	was	is	will be
We	were	are	will be
You	were	are	will be
They	were	are	will be

Verbs carry the idea of being or action in the sentence. Verbs are classified in many ways. Some verbs require an object to complete their meaning. A verb can be both transitive and intransitive. Verbs are also can be classified as either finite or non-finite. A finite verb makes an assertion or expresses a state of being and can stand by itself as the main verb of a sentence while non-finite verbs (think "unfinished") 

cannot, by themselves.

There are only four basic forms. Instead of forming complex tense forms with endings, English uses auxiliary verb forms. English does not even have a proper ending for future forms; instead, we use auxiliaries such as "I am going to read this afternoon." or "I will read." or even "I am reading this book tomorrow." It would be useful, however, to learn these four basic forms of verb construction.