By the time you enter college you probably know the different forms that ordinary verbs can take. You know, for instance, that when you're writing in the present tense, you use the present tense form of the verb (known as the present infinitive). When you write in the past tense, you use another form of the verb (the simple past tense). The other major form a verb may take is known as the post participle, and it is the form we use when the verb is preceded by a past tense helping verb (like have, has, or had). Thus, we ordinarily choose one of these three forms of a verb with hardly a thought:

• I like pizza (present tense)
  
• I liked pizza (simple past)
  
• I have liked pizza (past participle)

Then there are verbs that aren't ordinary, the ones we call irregular verbs because they don't take their different forms in standard ways. Most writers occasionally have trouble remembering the basic forms of some of the irregular verbs. If you are in doubt about the principal parts of a particular irregular verb, go to your dictionary. There you will find the present infinitive (I begin), the simple past tense (I began), and the past participle (I have begun). For regular verbs, which form the past tense and the past participle simply by adding -d or -ed, you will find only the present infinitive.

The principal parts of several irregular verbs are listed below. Many of them are probably already familiar to you. Some may not be. You can also add to this list any other irregular verbs you may have used incorrectly.

PRESENT INFINITIVE	PAST TENSE	PAST PARTICIPLE
begin	began	begun
blow	blew	blown
break	broke	broken
bring	brought	brought
burst (same in each form)	burst	burst
choose	chose	chosen
come	came	come
dive	dived or dove	dived
do	did	done
draw	drew	drawn
drink	drank	drunk
drive	drove	driven
eat	ate	eaten
fall	fell	fallen
fly	flew	flown
forget	forgot	forgotten
freeze	froze	frozen
get	got	gotten
give	gave	given
go	went	gone
hang (meaning to suspend)	hung	hung
hang (meaning to execute)	hanged	hung
know	knew	known
lay (to place)	laid	laid
lead	led	led
lie (to lie down, recline)	lay	lain
ride	rode	ridden
ring	rang	rung
rise	rose	risen
run	ran	run
see	saw	seen
seek	sought	sought
sing	sang	sung
sink	sank	sunk
speak	spoke	spoken
spring	sprang	sprung
steal	stole	stolen
swim	swam	swum
swing	swung	swung
take	took	taken
tear	tore	torn
threw	threw	thrown
woke	woke or waked	woken or waked
wear	wore	worn
write	wrote	written

Two pairs of irregular verbs - lie, lay, and sit, set - are particularly troublesome. The principal parts of lie (meaning to recline) are lie, lay, lain. The principal parts of lay (meaning to place) are lay, laid, laid. The distinction between the two verbs continues to be quite carefully observed in standard English.

LIE

PRESENT - Lie down for a while and you will feel better.
PAST - The cat lay in the shade and watched the dog carefully.
WITH –ING - His keys were lying on the table where he dropped them.
PAST PARTICIPLE - After he had lain down for a while, he felt better.

LAY

PRESENT - Lay the book on the table and come here.
PAST - He laid the book on the table and walked out the door.
WITH –ING - Laying the book on the table, he walked out the door.
PAST PARTICIPLE - Having laid the book on the table, he walked out the door.

The principal parts of sit (meaning to occupy a seat) are sit, sat, sat; the principal parts of set (meaning to put in place) are set, set, set.

SIT

PRESENT - Sit down and keep quiet.
PAST - The little girl sat in the corner for half an hour.
WITH –ING - Sitting down quickly, he failed to see the tack on the chair.
PAST PARTICIPLE - Having sat in the corner for an hour, the child became more reasonable.

SET

PRESENT - Set the basket on the table and get out.
PAST - Yesterday he set the grocery cartons on the table.
WITH –ING - Setting his glasses on the table, he challenged John to wrestle.
PAST PARTICIPLE - Having set the basket on the porch, Terry went home again.