should have + past participle

We use should have + the past participle (eaten, taken, gone, been, seen, walked, etc.) to express regret over a past action or to illustrate that an action that occurred was the wrong one. 

“The football game was great.  Manchester City dominated for whole game, but they lost.  They should have won,” said Tom.

“I didn’t see the game,” replied Paul. “I had tickets, but I gave them away.  I should have gone.”

“Yes, you should have.  I lost my voice from singing with the crowd: I shouldn’t have sung so loudly, but I couldn’t help myself.”

A usage that I have been hearing and seeing more and more frequently is “should have + simple past”—which is incorrect:

I should have went to the game. (incorrect)

I should have gone to the game. (correct)

You should have saw that movie. (incorrect)

You should have seen that movie. (correct)

He should not have ate that final piece of pizza. (incorrect)

He should not have eaten that final piece of pizza. (correct)

Remember that “should (not) have” must always be followed by a past participle.  Here is a list of some commonly confused past participles:

verb	past simple	past participle
arise	arose	arisen
awake	awoke	awoken
be	was/were	been
become	became	become
begin	began	begun
blow	blew	blown
break	broke	broken
choose	chose	chosen
do	did	done
drink	drank	drunk
eat	ate	eaten
fall	fell	fallen
forbid	forbade	forbidden
forget	forgot	forgotten
forgive	forgave	forgiven
give	gave	given
go	went	gone
grow	grew	grown
hide	hid	hidden
know	knew	known
run	ran	run
see	saw	seen
show	showed	shown
sing	sang	sung
steal	stole	stolen
swear	swore	sworn
tear	tore	torn
write	wrote	written

Resources

The Grammar in Use series by Cambridge University Press has numerous exercises for most grammatical problems (Unit 32 in Grammar in Use by Raymond Murphy and Roann Altman addresses the modal “should” in its various forms); the series runs from Basic to Advanced, so it can help with most problems.

Commas with Restrictive and Non-restrictive Clauses

“Who” is a relative pronoun that refers to people: “who” replaces a person’s name (e.g. Peter, Paul, Mary), a person as represented by a common noun (e.g. my doctor, our friend, an astronaut), or people as represented by a pronoun (e.g. he, she, they).  “Who” can begin both restrictive and non-restrictive clauses—groups of words that provide more information about the person whom “who” has replaced. 

Restrictive clauses provide essential information, information that is essential to the sentence and could not be removed without drastically changing the sense of the sentence.  Non-restrictive clauses provide additional information, information that could be removed and the sentence would not lose much sense.  Restrictive clauses do not need commas; non-restrictive clauses do.  The following examples show the difference.

Restrictive clause: The person who used to be the principal at my high school is now the principal at my son’s school.

If we removed “who used to be the principal at my high school” from the sentence, our readers might not understand it. For instance, “The person is now the principal at my son’s school” would leave readers wondering about the identity of “the person.” “Who used to be the principal at my high school” is therefore essential because it specifies the person for the readers.  Because the clause with “who” is essential to the sentence, we do not put commas around it.

Non-restrictive clause: Joe Peterson, who used to be the principal at my high school, is now the principal at my son’s school.

If we removed “who used to be the principal at my high school” from the sentence, our readers would still understand it:  “Joe Peterson is now the principal at my son’s school” still makes sense. “Who used to be the principal at my high school” only tells us a bit more about Joe Paterson.  Because the clause with “who” is non-essential to the sentence, we put commas around it.  (Think about non-restrictive clauses as parenthetical asides.)

Though the next two examples may appear to be identical, the commas make a significant difference when we think about them relative to the previous examples:

My wife who is 34 years old works in the Marine Biology Department.

My wife, who is 34 years old, works in the Marine Biology Department.

If “who is 34 years old” is essential to the sentence (as in the first example), I would appear to be a polygamist: in many cultures, I can only legally have one wife.  The sense of the sentence is that I have at least two wives; one of them is 34 years old.  It is more likely that “who is 34 years old” is only additional information about my one wife, and the clause should therefore be placed in commas (as in the second example).

References

Hacker, Diana.  A Writer’s Reference.  5^th ed. Boston: Bedford/St. Martin’s: 2003.

Honegger, Mark.  English Grammar for Writing.  Boston: Houghton Mifflin: 2005.

Sabin, William A. and Sheila A. O`Neill.  The Gregg Reference Manual: Third Canadian Edition. Toronto: Magraw-Hill Ryerson, 1986.