When you’re talking about a past action that was a mistake, you may hesitate between “should have not” and “should not have.” The two phrases contain the same words, but their normal word order is different. This confusion often appears in sentences such as “I should not have said that” or “She should have not gone there.” Standard English strongly favors should not have, and shouldn’t have is its common contracted form.
Quick Answer
Should not have is the normal and preferred form when you want to say that a past action was wrong, unwise, inappropriate, or something that should have been avoided.
| Form | Standard usage | Meaning | Example |
| should not have | Yes, normal | A past action was not advisable or should have been avoided | I should not have said that. |
| shouldn’t have | Yes, normal contraction | Same meaning as “should not have” | I shouldn’t have said that. |
| should have not | Uncommon and marked | Can occur in special contexts, especially with emphasis or contrast | He should have not only apologized but also fixed the problem. |
The basic structure is:
Subject + should + not + have + past participle
For example:
- I should not have waited so long.
- She should not have ignored the warning.
- We should not have canceled the meeting.
- He should not have spoken to her that way.
Oxford and the British Council both recognize should have as the past form of should, while should not have and shouldn’t have are used to discuss inappropriate or undesirable past actions.
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Meaning and Definition
Meaning of Should Not Have
Should not have means that someone did something in the past that was not advisable, appropriate, necessary, or desirable.
It often expresses regret, criticism, disapproval, or hindsight.
For example:
I should not have spent so much money.
This means the speaker spent the money, but now believes that spending it was a mistake.
Similarly:
You should not have told him the secret.
This means the person told him the secret, but the speaker believes that doing so was wrong or unwise.
The phrase does not always express personal regret. Depending on context, it can also express an expectation about a past situation. For example:
The package should not have arrived yet.
Here, the speaker is saying that the package was not expected to have arrived by that time. Oxford gives similar uses of should for expectations about past events.
Definition of Should Not Have
Should not have + past participle is a negative modal-perfect construction used to refer to a past action or situation that was considered wrong, inappropriate, undesirable, or contrary to what was expected.
Its grammatical structure is:
should + not + have + past participle
Examples include:
- should not have gone
- should not have said
- should not have eaten
- should not have taken
- should not have ignored
The modal should comes first, not makes the construction negative, have forms the perfect infinitive, and the final verb appears as a past participle.
Meaning of Should Have Not
Should have not is not normally the form used to express ordinary regret or criticism about a past action.
In most sentences, native speakers would naturally use should not have instead.
For example:
I should not have called him.
is the normal sentence.
The alternative:
I should have not called him.
may occasionally occur, particularly when not is being deliberately emphasized or contrasted with another part of the sentence. However, it is much less natural as the ordinary way of expressing the idea. Language discussions also document contexts where this word order can be used for special emphasis.
Therefore, learners should not treat should have not as the standard replacement for should not have.
Definition of Should Have Not
Should have not can be understood as a marked word order in which not is placed after the perfect auxiliary have. It is uncommon in ordinary English and can sound awkward when used simply to mean that an action should not have happened.
In ordinary writing and conversation, use:
should not have + past participle
rather than:
should have not + past participle
There are contexts where speakers deliberately place not later in the verb phrase for emphasis or contrast, so calling every occurrence strictly ungrammatical would be too broad. The important point for learners is that should not have is overwhelmingly the normal construction for this meaning.
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Main Difference
The main difference is word order and emphasis.
In ordinary negative sentences with should, the negative word not follows the modal verb:
should + not + have + past participle
For example:
She should not have left early.
The sentence means that leaving early was not the right thing to do.
The same idea can be expressed more naturally with the contraction:
She shouldn’t have left early.
English places negation after the modal or first auxiliary in this type of verb phrase. Cambridge’s grammar guidance explains that when a modal occurs with other auxiliary verbs, the modal occupies the first position in the verb structure.
| Construction | Typical meaning | Naturalness |
| should have | Something was advisable, expected, or appropriate | Very natural |
| should not have | Something was not advisable or should have been avoided | Very natural |
| shouldn’t have | Same meaning as “should not have” | Very natural |
| should have not | Marked or emphatic alternative in limited contexts | Much less common |
Should Have vs. Should Not Have
These two constructions have opposite recommendations.
You should have called me.
This suggests that calling was the right thing to do, but it did not happen.
You should not have called me.
This suggests that calling was the wrong thing to do, and the context normally indicates that the call happened.
The British Council describes should have + past participle as a way to talk about an action that was advisable in the past, while shouldn’t have + past participle refers to an action that was done but was not advisable.
Which One Is Correct?
For ordinary English, should not have is the correct and natural choice.
You can also use shouldn’t have, which is simply the contracted form of should not have.
Correct
I should not have said that.
Correct
I shouldn’t have said that.
Less natural or marked
I should have not said that.
The third sentence may occasionally be found, but it should not be your default construction. Some grammar discussions note that should have not can be used in special contexts where the speaker wants to emphasize or contrast the negative element.
So, if you’re writing an email, essay, article, school assignment, or professional message, should not have or shouldn’t have is the safer and more natural choice.
Grammar and Usage
The grammar becomes easier once you understand how modal verbs work.
The Basic Structure
The normal negative pattern is:
Subject + should + not + have + past participle
Examples:
- I should not have gone.
- You should not have worried.
- She should not have taken it.
- They should not have canceled the event.
- We should not have waited.
After should, use the base form have, not had.
Correct:
I should not have gone.
Incorrect:
I should not had gone.
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Why “Have” Is Used
In this construction, have is part of the perfect infinitive.
The structure is:
should + have + past participle
For example:
should have gone
should have eaten
should have called
When you make that construction negative, not normally follows should:
should + not + have + gone
The result is:
should not have gone
Oxford identifies should have as the form used to refer to past situations and specifically lists should not have and shouldn’t have for past actions that were wrong or inappropriate.
Should Not Have Been
The same structure applies when the main verb is be.
Correct:
I should not have been there.
Correct:
She shouldn’t have been so worried.
Correct:
They should not have been late.
The pattern is:
should + not + have + been
Not:
should + have + not + been
The second version may sometimes be encountered for special emphasis, but it is not the normal construction for learners to use.
Should Not Have to
Be careful with should not have and should not have to.
They do not mean the same thing.
You should not have worked so late.
This means working late was a mistake or was not advisable.
You should not have to work so late.
This means you ought not to be required to work late.
The second sentence concerns obligation or necessity, not a completed past action. Context and the verb form after have make the difference clear.
How to Use Should Not Have
Use should not have + past participle when looking back at a past action and saying that the action was not the right thing to do.
Expressing Regret
You can use it to talk about something you wish you had not done.
I should not have eaten so much.
I should not have stayed up so late.
I should not have spent all my money.
The speaker is evaluating a completed past action from a later point in time.
Criticizing an Action
You can also use it to criticize someone else’s past behavior.
You should not have spoken to your manager like that.
He should not have shared the private information.
They should not have ignored the warning.
The strength of the criticism depends on context and tone.
Talking About What Was Expected
Should have can also express expectation.
The train should have arrived by now.
With not, the meaning becomes a negative expectation:
The train should not have arrived yet.
This does not necessarily mean that anyone did something wrong. It can simply mean that the speaker did not expect the event to have happened already. Oxford lists this expectation use of should have in its American English dictionary.
Examples
Examples of Should Not Have
Everyday conversation
I should not have eaten that last slice of cake.
You should not have worried so much.
I should not have stayed up until midnight.
Professional communication
We should not have delayed the project without informing the client.
The team should not have ignored the customer’s complaint.
I should not have sent the report before checking the figures.
Academic context
The researcher should not have excluded those results without explanation.
Students should not have relied on an unverified source.
Social situations
I should not have interrupted you.
She should not have shared that private conversation.
We should not have arrived without calling first.
Examples of Shouldn’t Have
Shouldn’t have means exactly the same thing as should not have, but it is contracted and usually sounds more conversational.
I shouldn’t have said that.
You shouldn’t have opened the message.
We shouldn’t have waited so long.
He shouldn’t have driven after drinking.
They shouldn’t have canceled the appointment without notice.
Oxford lists shouldn’t as the standard short form of should not.
Examples of Should Have
Understanding the positive form makes the negative form easier.
I should have called you.
She should have checked the address.
We should have arrived earlier.
They should have told us about the change.
In each case, the speaker identifies something that would have been the better, expected, or appropriate action.
Examples of Should Have Not
Because should have not is unusual, it is better not to use it as your ordinary negative construction.
For example, instead of:
I should have not said that.
write:
I should not have said that.
Instead of:
She should have not gone there.
write:
She should not have gone there.
However, unusual word order can sometimes appear when a writer is deliberately focusing on the negative element or building a contrast. This is a specialized use, not the normal pattern learners should imitate.
Common Mistakes
Mistake 1: Writing “Should Have Not” as the Default Negative
Incorrect or unnatural as the ordinary choice:
I should have not told him.
Preferred:
I should not have told him.
The normal position of not is immediately after the modal should.
Mistake 2: Writing “Should Haven’t”
Incorrect:
I should haven’t said that.
Correct:
I should not have said that.
Correct contraction:
I shouldn’t have said that.
The contraction shouldn’t combines should and not. It does not combine have and not.
Mistake 3: Writing “Should Not Had”
Incorrect:
She should not had gone there.
Correct:
She should not have gone there.
After a modal verb such as should, use the base form have.
Mistake 4: Confusing “Should Have” With “Should Have To”
Compare:
You should have called me.
This refers to a past action that would have been advisable.
You should have to call me.
This is a different and unusual construction concerning obligation or expectation, not the ordinary past form.
A particularly useful distinction is:
You should not have called me.
versus:
You should not have to call me.
The first evaluates a past call. The second says that calling should not be necessary or required.
Mistake 5: Using “Should Of”
Incorrect:
I should of called you.
Correct:
I should have called you.
Correct contraction:
I should’ve called you.
In speech, should’ve can sound similar to “should of,” which helps explain why the error occurs in writing. But should of is not the standard written construction.
Linguistic Insight
The key linguistic issue is the placement of negation within a verb phrase.
English modal verbs such as should, could, would, might, may, and must can combine with auxiliary verbs. When a modal is followed by another auxiliary, the modal occupies the first position in the verb chain.
Consider:
should + have + gone
Add negation:
should + not + have + gone
This produces:
should not have gone
The word not normally follows the first modal or auxiliary element that carries the grammatical force of the negative construction. Cambridge’s grammar guidance describes this ordering in structures containing a modal plus auxiliary verbs.
This is why English speakers naturally produce:
should not have gone
rather than:
should have not gone
The second arrangement is not impossible in every conceivable context. English allows speakers to manipulate word order for emphasis and contrast. But that does not make the less common arrangement the normal choice.
This distinction matters because grammar is not always a simple matter of declaring every uncommon construction “wrong.” Real English includes marked constructions that speakers use for particular effects. The practical rule for standard everyday English remains simple: use should not have.
Usage Tips
Remember the Pattern
Use this formula:
Should + not + have + past participle
For example:
should not have gone
should not have eaten
should not have said
should not have taken
Use “Shouldn’t Have” in Conversation
When speaking informally, shouldn’t have is very natural.
I shouldn’t have done that.
In more formal writing, you may prefer:
I should not have done that.
Both forms are grammatically correct. Oxford lists shouldn’t as the contracted form of should not.
Think “Should + Not”
A simple memory aid is to attach not directly to should:
should + not
Then add:
have + past participle
So:
should + not + have + done
This gives you:
I should not have done it.
Do Not Change “Have” to “Had”
Even though you’re discussing the past, the construction is:
should have, not should had.
The past meaning comes from the modal-perfect structure, while have remains in its base form.
Expert Suggestion
If you’re unsure whether to use should have not or should not have, choose should not have in normal writing and conversation.
For most learners, the easiest pattern to remember is:
I should not have + past participle.
For example:
I should not have complained.
I should not have reacted that way.
I should not have ignored the advice.
If you want a more conversational tone, use shouldn’t have:
I shouldn’t have complained.
I shouldn’t have reacted that way.
I shouldn’t have ignored the advice.
Only consider should have not when the sentence has a specific emphasis or contrast that makes the unusual word order meaningful. In ordinary English, there is no advantage in choosing it.
Summary
Should not have is the normal and preferred construction for expressing that a past action was wrong, unwise, inappropriate, or contrary to what was expected. Its standard structure is should + not + have + past participle.
Shouldn’t have is the natural contraction of should not have. By contrast, should have not is much less common and can sound awkward when used simply as a negative. It may appear in marked contexts involving emphasis or contrast, so it is too broad to call every occurrence strictly ungrammatical.
For everyday English, professional writing, academic work, and ESL learning, the safest pattern is simple: should not have or shouldn’t have.
Frequently Asked Questions
Is “Should Have Not” correct?
Should have not can occur in limited contexts, especially when the speaker wants to emphasize or contrast not, but it is not the normal way to form this negative. For ordinary English, use should not have or shouldn’t have.
Is “Should Not Have” correct?
Yes. Should not have is the standard negative construction. It follows the pattern should + not + have + past participle, as in “You should not have said that.” Oxford specifically lists should not have and shouldn’t have for talking about past actions.
Is “Shouldn’t Have” correct?
Yes. Shouldn’t have is the contracted form of should not have. It is very common in conversation and informal writing. For example, “I shouldn’t have waited” means that waiting was not the right thing to do.
What is the difference between “Should Have” and “Should Not Have”?
Should have usually says that an action was advisable or appropriate but did not happen. Should not have says that an action was not advisable or should have been avoided. For example, “You should have called” contrasts with “You should not have called.”
Does “Should Not Have” express regret?
It often does. A speaker may use should not have to express regret about something they did in the past. For example, “I should not have spent so much money” shows that the speaker now regrets the spending or considers it a poor decision.
Can “Should Not Have” express criticism?
Yes. It can criticize another person’s past action. For example, “You should not have shared that information” means the speaker believes sharing it was wrong, inappropriate, or unwise.
Can “Should Not Have” express an expectation?
Yes. Should can express expectation as well as advice. For example, “The train should not have arrived yet” means the speaker did not expect the train to have arrived by that time.
Should I write “Should Not Had” or “Should Not Have”?
Use should not have, not should not had. After the modal verb should, the auxiliary remains in its base form have. The past participle comes after it, as in “should not have gone.”
Is “Should Haven’t” correct?
No. Should haven’t is not the standard construction. Use should not have or its contraction shouldn’t have. For example, write “I shouldn’t have said that,” not “I should haven’t said that.”
Is “Should Have Not” always wrong?
No. It is too absolute to say that every occurrence is impossible. Should have not can appear in unusual contexts where the writer is emphasizing or contrasting the negative element. However, it is much less natural than should not have for ordinary negative statements.
Which form should I use in formal writing?
Use should not have when you need the full form. It is clear, standard, and natural. Shouldn’t have is also correct but is more conversational. Should have not should generally be avoided unless the particular sentence requires its marked emphasis or contrast.
What is the correct sentence: “I should have not done it” or “I should not have done it”?
The normal and preferred sentence is “I should not have done it.” You can also say “I shouldn’t have done it.” Both clearly express the idea that doing it was a mistake or was not advisable.
What is the structure of “Should Not Have”?
The structure is subject + should + not + have + past participle. For example: “She should not have gone,” “They should not have waited,” and “I should not have said that.” This is commonly called a negative modal-perfect construction.
Can “Should Not Have” and “Should Have Not” mean the same thing?
In many contexts, they can be understood as expressing essentially the same idea, but should not have is the normal word order. Should have not can carry special emphasis or contrast in some contexts. For ordinary communication, use should not have.
