When one has reached maturity in the art, one will have a formless form. It is like ice dissolving in water. When one has no form, one can be all forms; when one has no style, he can fit in with any style. - Bruce Lee

Verbs are distinguished by singular or plural and by person (first, second, third). Verbs usually have a different form in the third person present tense: I, you, we, they walk. He, she, it walks. He, she and it are third person present tense.

“To be or not to be, –that is the question:–
Whether ’tis nobler in the mind to suffer
The slings and arrows of outrageous fortune
Or to take arms against a sea of troubles,
And by opposing end them?”
-Shakespeare, From Hamlet (III, i, 56-61)

Exception: “To be” has a greater inflection.

A finite verb can be one word or a group of words to show tense: walk, walked. If it is a group of words watch for:

Modal Auxiliaries - can, could, may, might, shall, should, must, will, and would

Modal - noting or pertaining to mood.

Perfect Auxiliary - part of the verb “have” plus an “-ing” ending

Perfect - Expressing action completed prior to a fixed point of reference in time

Progressive Auxiliary - part of the verb “be” with an “-ing” ending

Progressive - Designating a verb form that expresses an action or condition in progress

Passive Auxiliary - part of the verb “be” plus an “-en” or “-ed” ending

Passive - Verb form or voice used to indicate that the grammatical subject is the object of the action or the effect of the verb

Main Verb - The main verb is the most important verb in a sentence; without it, the sentence would not be complete. (source: UsingEnglish.com)

Main Verb - a word used as the final verb in a verb phrase, expressing the lexical meaning of the verb phrase

The modal auxiliary is added to the main verb and the perfect, progressive or passive auxiliaries surround the next form of the finite verb.