A verb is an action, occurrance, or state of existence.

But verbs are anything but simple. Verbs can be classified in two general categories: dynamic verbs (also known as lexical verbs), which show physical actions, and static verbs, which show states of existence.


There are three types of static verbs: stative verbs (also called mental action verbs) show how a subject senses, perceives, understands, possesses, or feels about an object; linking verbs (also called copula verbs) show how a subject exists by linking the subject with a predicative or indicates how a speaker senses, perceives, understands, possesses, or feels about a subject; and helping verbs (also called auxiliary verbs) clarify the state of how another action exists.

A verb also conveys tense (when an action happened), aspect (the duration of the action), valency (the number of things affected by the action), and mood (the tone the action sets). ​Modifying a verb to fit the proper conditions is verb conjugation, and there are conventions for how verbs conjugate. In brief:

• pure present verb: basic form found in a dictionary
• plural present verb: add -s or -es
  
• present participle: add -ing
  
• past verbs: add -ed
• past participle: add -ed
  

But some verbs don't play by the rules.

Strong verbs, which are also called irregular verbs, break at least one of these conjugation conventions. Why? Because English is a mess. English started as a fusion of Old Norse and Proto-German, which each had different ways of creating past tense (change vowel to A vs. add -ed), past participles (-en vs. -ung), and present participles (-en vs. -ing). When the printing press became widespread and spelling started to be standardized, most words in English shifted to accepting the German-influenced endings instead of the Norse-influenced ones. Middle English also saw -ung subsumed by -ing to avoid spelling errors. The goal was a more unified and logical English.

But some words resisted.

Or rather, people resisted the new changes for some very common verbs because they were used to them. At first, early rulers interested in linguistics (i.e., the French Saxons) tried to force conformity for these stubborn verbs as well as other words, but popular use eventually won out. These verbs that were strong enough to resist linguistic change are called strong verbs, though they sometimes are also referred to as irregular verbs.

​There aren't too many strong verbs in English, but all of them are frequently used. Here is the full list. We'll start with the most common and weirdest to conjugate, the Hamlet verbs.

Then there're the defective verbs. Like other strong verbs, defective verbs resisted normal conjugation, but by doing so, they don't possess all five verb forms, infinitive forms, or gerund forms. That's why these verbs are defective—they don't do everything a verb should.

PURE PRESENT	PLURAL PRESENT	PRESENT PARTICIPLE	PAST	PRESENT PARTICIPLE	WORD MEANING
can	can	NONE	could	NONE	is able to
may	may	NONE	might	NONE	is possible
must	must	NONE	NONE	NONE	is necessary
ought	ought	NONE	NONE	NONE	is probable
shall	shall	NONE	should	NONE	is going to
will	will	NONE	would	NONE	is going to
beware	beware	NONE	NONE	NONE	to be alert
begone	begone	NONE	NONE	NONE	to leave

Next are the invariable verbs—these don't change forms at all between present and past tense. While invariable verbs resisted conjugation like other strong verbs, the resistance has come from modern usage, not older usage. Enough of the population has used the pure present form for both past forms that there is now no difference.

PURE PRESENT	PAST	PAST PARTICIPLE	WORD MEANING
bet	bet	bet	to wager
bid	bid	bid	to offer money

Finally, the rest of the strong verbs:

PURE PRESENT	PAST	PAST PARTICIPLE	WORD MEANING
bear	bore	born	to give birth
bear	bore	borne	to carry a load
beat	beat	beaten	to hit or defeat
become	became	become	to shift existence
beget	begot	begotten	to father
begin	began	begun	to start
bend	bent	bent	to reshape
beseech	beseeched	besought	to beg
bid	bid	bade	to tell
Value