The Six Basic Verb Forms

Six basic verb forms are used to create the entire tense system of English: base form, present,
past, infinitive, present participle, and past participle. These forms are illustrated in
the following chart by the regular verb walk and the irregular verb fly.

base form = = walk = fly
present = walk | walks = fly | flies
past = walked = flew
infinitive = to walk = to fly
present participle = walking = flying
past participle = walked = flown