When you’re talking about something that was wrong or unwise in the past, you may wonder whether to say “should have not” or “should not have.” Both word orders can appear in English, but they are not equally natural or common. In most situations, “should not have” is the standard and preferred form. This article explains why, when the less common form can occur, and how to use both constructions correctly.
Quick Answer
“Should not have” is the normal and preferred form in standard English. Use it when you mean that someone was advised against doing something in the past, or that an action was wrong, unwise, inappropriate, or regrettable.
| Form | Standard? | Typical Use | Example |
| should not have | Yes | Normal past negative advice or criticism | You should not have said that. |
| shouldn’t have | Yes | Contracted, common in everyday English | You shouldn’t have said that. |
| should have not | Rare and marked | Possible when not is deliberately emphasized or attached to the following action | You should have not only apologized but also corrected the mistake. |
Oxford’s learner dictionary explains that should have is used to talk about past situations and that should not have or shouldn’t have expresses that something was a bad idea or the wrong thing to do.
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For ordinary writing and conversation, choose “should not have” or “shouldn’t have.”
Meaning and Definition
Meaning of Should Not Have
Should not have means that an action in the past was something a person was expected, advised, or morally expected not to do.
For example:
You should not have ignored her message.
The sentence means that ignoring her message was not the right thing to do.
The construction can express regret, criticism, disapproval, or a judgment about a past action.
Definition of Should Not Have
Should not have is a negative modal construction formed from should + not + have + past participle.
It refers to a past action or situation that the speaker considers undesirable, inappropriate, unnecessary, or contrary to what would have been better.
For example:
We should not have waited so long.
The speaker is looking back and saying that waiting was a mistake or was not advisable.
Meaning of Should Have Not
Should have not places not after the perfect auxiliary have. It can occur in English, but it is much less common and often sounds awkward when used simply as an alternative to should not have.
For example, instead of:
I should have not called him.
Most speakers would naturally say:
I should not have called him.
However, should have not can sometimes occur when the writer or speaker wants to give special emphasis to the negative action or when not belongs closely with what follows.
Definition of Should Have Not
Should have not can be understood as a construction in which should have is followed by a negative complement. It is not normally the preferred way to form a simple negative of should have.
It should therefore not be treated as a completely interchangeable everyday alternative to should not have.
For standard, natural communication, should not have is the safer choice.
Main Difference
The main difference is word order and naturalness.
In ordinary negative modal constructions, English normally places not after the modal verb:
should + not + have + past participle
For example:
She should not have left so early.
This follows the same general pattern seen with other modal verbs:
- could not have known
- might not have noticed
- would not have agreed
- must not have understood
- should not have waited
The unusual form should have not moves the negative element after have. That placement can produce a different emphasis or make the sentence sound marked, but it is not normally how speakers express ordinary past negative advice.
A useful comparison is:
| Construction | Naturalness | Meaning |
| You should not have called. | Very natural | Calling was a bad or inappropriate action. |
| You shouldn’t have called. | Very natural | Same basic meaning, more conversational. |
| You should have not called. | Unusual | Can place special emphasis on the negative action. |
The distinction is supported by usage discussions from English speakers and grammar references, which consistently identify should not have as the normal construction while noting that should have not can occur in unusual or emphatic contexts.
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Which One Is Correct?
“Should not have” is the correct and natural choice for ordinary English.
For example:
I should not have said that.
You should not have opened the email.
They should not have ignored the warning.
The contracted form shouldn’t have is also correct:
I shouldn’t have said that.
You shouldn’t have opened the email.
They shouldn’t have ignored the warning.
The form should have not is not best described as simply impossible. It can appear in carefully constructed sentences, particularly when not receives special emphasis or is closely connected to a following complement. However, using it as a direct substitute for should not have will often sound unnatural.
One language discussion gives the useful distinction that “should not have” normally negates the modal judgment, whereas “should have not” can place greater emphasis on the negative action itself.
So, if you’re unsure, use should not have.
Grammar and Usage
Should is a modal auxiliary verb. When it refers to a past action, it can be followed by have + past participle.
The basic affirmative pattern is:
Subject + should + have + past participle
You should have called me.
The negative pattern is:
Subject + should + not + have + past participle
You should not have called me.
The contraction is:
Subject + shouldn’t + have + past participle
You shouldn’t have called me.
The past participle is essential after have in this construction.
For example:
- should have gone
- should have seen
- should have known
- should have finished
- should have taken
Not:
- should have went
- should have saw
- should have knew
- should have finish
- should have took
The negative form simply places not after should:
She should not have gone.
This is why should not have is the normal structure.
Should Not Have for Past Actions
Use should not have + past participle when judging a past action.
You should not have spoken to him that way.
The speaker believes the past action was inappropriate.
Should Not Have for Regret
The construction can also express personal regret.
I should not have spent so much money.
The speaker now believes spending that money was a mistake.
Should Not Have for Criticism
It can express criticism of another person’s past behavior.
He should not have shared confidential information.
The speaker believes sharing the information was wrong or inappropriate.
Shouldn’t Have in Conversation
Shouldn’t have is simply the contracted form of should not have.
I shouldn’t have complained.
You shouldn’t have worried.
They shouldn’t have canceled the meeting.
The contraction is especially common in speech and informal writing.
How to Use Should Not Have
The easiest way to use this construction correctly is to remember its basic pattern:
Subject + should not have + past participle
For example:
I should not have eaten so much.
She should not have told everyone.
We should not have waited.
They should not have canceled the appointment.
The construction looks backward from the present and evaluates something that happened, or failed to happen, in the past.
For Personal Mistakes
Use it when you recognize that your own past action was a mistake.
I should not have sent that email without checking it.
I should not have stayed up so late.
For Other People’s Actions
Use it when commenting on someone else’s behavior.
You should not have spoken to your manager like that.
He should not have shared her private information.
For Past Situations
It can also describe a situation that would have been better avoided.
We should not have traveled during the storm.
They should not have entered the building without permission.
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Examples
Examples of Should Not Have
I should not have eaten the entire cake.
You should not have ignored her advice.
She should not have left without telling anyone.
We should not have booked the hotel without checking the reviews.
He should not have sent the report before proofreading it.
They should not have canceled the meeting at the last minute.
I should not have assumed that everyone agreed with me.
You should not have shared that information publicly.
The company should not have released the announcement before confirming the facts.
Students should not have submitted the assignment without checking the instructions.
Examples of Shouldn’t Have
I shouldn’t have stayed up so late.
You shouldn’t have worried about it.
She shouldn’t have taken that route.
We shouldn’t have trusted the first estimate.
He shouldn’t have spoken so harshly.
They shouldn’t have left the office unlocked.
In each case, shouldn’t have has the same basic meaning as should not have.
Examples of Should Have Not
The less common word order can occur when the negative element receives special emphasis or forms part of a larger contrast.
For example:
You should have not only apologized but also explained what happened.
Here, not is part of the paired construction not only … but also, so moving it after have is natural.
Another example is:
She should have not merely accepted the criticism but considered whether it was justified.
Here, not merely introduces a contrast and is directly connected to what follows.
These examples are different from simply saying:
She should have not accepted the criticism.
In that ordinary sentence, She should not have accepted the criticism is much more natural.
Common Mistakes
Using Should Have Not as the Normal Negative
Incorrect or unnatural in ordinary usage:
I should have not called him.
Preferred:
I should not have called him.
The mistake happens because learners may treat have as the main verb that needs negation. In this construction, however, should is the modal auxiliary, so the normal position for not is immediately after should.
Writing Should Haven’t
Incorrect:
I should haven’t called her.
Correct:
I shouldn’t have called her.
English does not form the contraction by combining should + have + not in this way. The standard contraction is shouldn’t, followed by have.
Confusing Should Not Have With Should Not Have To
These constructions have different meanings.
You should not have called him.
This means calling him was something you ought not to have done in the past.
You should not have to call him.
This means you ought not to be required to call him.
The second sentence concerns an obligation or requirement, while the first evaluates a past action.
Using Should Of Instead of Should Have
Incorrect in standard writing:
I should of called you.
Correct:
I should have called you.
The confusion comes from the pronunciation of should’ve, which sounds similar to “should of” in casual speech.
Treating Less Common as Automatically Incorrect
It is too simplistic to say that every occurrence of should have not is grammatically impossible. English allows unusual word orders in particular contexts, especially when not has contrastive emphasis or forms part of a larger phrase.
However, frequency and naturalness matter. For ordinary negative statements, should not have is overwhelmingly the better choice.
Linguistic Insight
The construction becomes easier to understand when you look at how English handles negation.
In a verb phrase containing a modal auxiliary, not normally follows the modal:
should not
could not
would not
might not
must not
When another auxiliary follows the modal, that auxiliary comes after not:
should not have gone
could not have known
would not have happened
This creates the familiar pattern:
modal + not + perfect auxiliary + past participle
So in should not have gone, the grammatical structure is:
- should = modal auxiliary
- not = negative marker
- have = perfect auxiliary
- gone = past participle
This structure explains why should not have feels natural to English speakers.
The unusual form should have not becomes more acceptable when not has a special relationship with what follows. For example, in should have not only apologized but also explained, the word not is part of the established pair not only … but also.
This distinction is important because grammar is not simply about declaring one sequence “right” and another “wrong.” Word order can affect emphasis, structure, and interpretation.
Usage Tips
Remember these simple rules:
- For normal past negative advice, use should not have.
- In conversation, shouldn’t have is equally natural.
- Follow have with a past participle.
- Do not write should haven’t.
- Do not confuse should not have with should not have to.
- Do not assume every unusual occurrence of should have not is automatically ungrammatical.
- If you’re writing formal or professional English, should not have is the clearest choice.
- Look for special structures such as not only … but also before deciding that should have not is wrong.
A simple memory aid is:
Should + not + have + past participle
You should not have gone.
Expert Suggestion
As a grammar teacher, I recommend using should not have whenever you’re expressing ordinary criticism, regret, or advice about a past action. It is clear, natural, and widely understood in both American and British English.
If you’re writing for school, work, or professional communication, there is little reason to choose should have not when should not have expresses the meaning you want.
For everyday speech, shouldn’t have is also an excellent choice:
I shouldn’t have said that.
Think of should not have as the full form and shouldn’t have as its natural contraction.
Summary
Should not have is the standard and preferred construction for expressing that a past action was wrong, unwise, inappropriate, or something that should have been avoided.
The normal structure is:
should + not + have + past participle
For example:
You should not have ignored the warning.
Shouldn’t have is the contracted form and has the same basic meaning.
Should have not can occur in English, particularly when not has special emphasis or belongs to a larger structure such as not only … but also. However, it is much less natural as a simple alternative to should not have.
When in doubt, use should not have.
Frequently Asked Questions
Is “should not have” correct?
Yes. Should not have is grammatically correct and is the normal way to express negative advice, criticism, regret, or judgment about a past action.
Is “should have not” correct?
It can occur in specific contexts, especially when not receives special emphasis or forms part of a larger construction. However, it is not the usual choice for a simple negative. Should not have is normally preferred.
Which is more natural, “should have not” or “should not have”?
Should not have is much more natural for ordinary English. Native speakers commonly use it when saying that someone should have avoided a past action.
Is “shouldn’t have” the same as “should not have”?
Yes. Shouldn’t have is the contracted form of should not have. Both normally express the same meaning.
What does “should not have” mean?
It means that a person ought not to have done something in the past. It can express regret, criticism, disapproval, or the idea that a past action was unwise.
Can I use “should have not” in formal writing?
You can encounter it in formal or carefully structured writing, but it is usually unnecessary when you simply mean should not have. For clarity and naturalness, use should not have unless the context specifically calls for the unusual word order.
Is “I should have not done it” grammatically correct?
It is possible in a marked or emphatic context, but I should not have done it is the natural choice when you mean that doing it was a mistake or something you ought to have avoided.
Why does “should not have” sound more natural?
English normally places not immediately after a modal auxiliary such as should. The resulting structure is should + not + have + past participle, which is the standard pattern for this type of negative construction.
Is “should haven’t” correct?
No. Should haven’t is not the standard contraction. Use shouldn’t have instead.
What is the difference between “should not have” and “should not have to”?
Should not have evaluates a past action. Should not have to refers to an obligation or requirement that someone should not be expected to face.
For example:
You should not have apologized.
You should not have to apologize.
The first concerns a past action. The second concerns whether an apology should be required.
Can “should have not” be correct with “not only”?
Yes. A construction such as “She should have not only apologized but also explained what happened” is natural because not only … but also is a paired structure. Here, not is not simply being placed after have to make the entire verb phrase negative.
Should I use “should not have” in professional writing?
Yes. Should not have is clear and standard, making it a good choice for professional, academic, and formal writing. You can use shouldn’t have in less formal communication.
What is the easiest way to remember the correct form?
Remember this pattern:
Subject + should not have + past participle
For example:
I should not have complained.
She should not have left.
They should not have waited.
When you want the normal negative form, put not after should.
