Should Have Not or Should Not Have: Correct Usage

When choosing between “should have not” and “should not have,” the usual and natural choice is “should not have.” It is the standard construction for saying that a past action was wrong, unwise, unnecessary, or regrettable. For example, “I should not have said that” means the speaker believes saying it was a mistake.

However, “should have not” is not completely impossible in English. It can occur in unusual contexts when not is deliberately emphasized or contrasted with another action. In ordinary English, especially in formal and professional writing, “should not have” is the better choice.

Is “Should Have Not” or “Should Not Have” Correct?

“Should not have” is the normal and preferred form.

The basic structure is:

Subject + should + not + have + past participle

For example:

• I should not have said that.
• She should not have gone there.
• They should not have ignored the warning.
• We should not have waited so long.

Oxford Learner’s Dictionaries explains that should have is used to refer to the past, while should not have or shouldn’t have is used to discuss something in the past that was a bad idea or the wrong thing to do.

“Should have not” may occasionally be found, particularly when the writer wants to give special emphasis to not, but it is much less natural than “should not have.”

Should Not Have: Meaning and Grammar

Should not have + past participle is a modal perfect construction.

The pattern is:

should + not + have + past participle

Here, should is a modal verb, not makes the construction negative, have forms the perfect infinitive, and the past participle describes the completed action.

For example:

I should not have eaten so much.

This means that the speaker ate too much and now believes that doing so was a mistake.

The construction commonly expresses:

• regret
• criticism
• a past mistake
• an action that was unnecessary
• an action that was inappropriate
• advice about a past situation

English grammar references describe should have + past participle as a way of talking about past situations that did not happen as expected, while should not have + past participle commonly refers to an unwanted action that actually happened.

Should Have Not: Meaning and Usage

“Should have not” places not after have:

should + have + not + past participle

This is unusual because English normally places the negative element after the first modal or auxiliary verb. When should is the first auxiliary or modal, the natural position for not is immediately after should.

Compare:

Natural:
I should not have said that.

Unusual:
I should have not said that.

The second version can sometimes be used for deliberate emphasis or contrast, but it is not the normal wording. Therefore, learners should generally choose “should not have.”

What Is the Difference Between “Should Have Not” and “Should Not Have”?

The two forms can communicate essentially the same idea in some contexts, but they differ in naturalness, emphasis, and normal grammatical placement.

Form	Typical use	Naturalness
should not have	Normal negative past advice, regret, or criticism	Very natural
shouldn’t have	Informal version of “should not have”	Very natural
should have not	Rare, usually emphatic or contrastive	Unusual

For everyday English, there is usually no reason to choose “should have not.”

For example:

Preferred:
You should not have opened the door.

More conversational:
You shouldn’t have opened the door.

Unusual:
You should have not opened the door.

The first two are the forms most speakers would naturally use.

Why Is “Should Not Have” More Natural?

English generally places not after the first auxiliary verb or modal in a verb phrase. Cambridge Grammar notes that when a modal occurs with additional auxiliaries, the modal comes first in the verb structure.

In:

You should not have left.

the structure is:

• should = modal verb
• not = negative marker
• have = perfect auxiliary
• left = past participle

This produces the familiar negative modal perfect construction.

The same pattern occurs with other modal verbs:

• You could not have known.
• She might not have noticed.
• They would not have agreed.
• He must not have understood.
• We should not have waited.

Because this word order is firmly established, “should not have” sounds much more natural than “should have not.”

Should Not Have vs. Shouldn’t Have

“Shouldn’t have” is simply the contracted form of “should not have.”

Both are grammatically correct.

Should not have

This form is more suitable when you want a clear or somewhat formal style.

You should not have shared that information.

Shouldn’t have

This is very common in everyday conversation.

You shouldn’t have shared that information.

Cambridge lists should’ve as the contraction of should have, and standard English also uses shouldn’t as the contraction of should not.

Examples of “Should Not Have”

Here are natural examples of the preferred construction:

Regret

I should not have said those things.

The speaker regrets saying them.

A bad decision

We should not have taken that road.

The speaker believes taking the road was a poor decision.

Criticism

You should not have spoken to her that way.

The speaker believes the person’s behavior was inappropriate.

Unnecessary action

They should not have waited for us.

The speaker believes waiting was unnecessary.

Past mistake

He should not have spent all his money.

The speaker believes spending all the money was unwise.

Apology

I should not have blamed you.

The speaker recognizes that blaming the other person was wrong.

Examples of “Should Have Not”

In ordinary writing, these sentences are better rewritten with “should not have”:

Unusual:

I should have not called him.

Preferred:

I should not have called him.

Unusual:

She should have not accepted the offer.

Preferred:

She should not have accepted the offer.

Unusual:

They should have not ignored the warning.

Preferred:

They should not have ignored the warning.

Unusual:

We should have not gone there.

Preferred:

We should not have gone there.

The unusual versions may be understandable, but they do not sound as natural to most speakers.

Can “Should Have Not” Ever Be Correct?

There is an important nuance here. It is too strong to say that “should have not” is always grammatically impossible.

In certain contexts, speakers may place special emphasis on not, especially when contrasting one possible action with another.

For example:

We should have not simply ignored the problem, but investigated it immediately.

Even here, most writers would normally improve the sentence by using:

We should not have simply ignored the problem; we should have investigated it immediately.

Another possible use occurs when not itself is being emphasized:

You should have done anything but not that.

In carefully constructed or highly emphatic speech, unusual word order can occur for pragmatic reasons. Grammar discussions also recognize that “should have not” can occasionally be used to emphasize the negative, although it is rare and can sound awkward or affected.

Therefore, the best practical rule is:

Use “should not have” in normal English. Use “should have not” only when there is a specific reason to emphasize or contrast “not.”

Should Not Have vs. Should Have

It is also important not to confuse these two structures.

Should have

Should have + past participle usually expresses what was advisable, expected, or appropriate in the past.

You should have called me.

This means calling me would have been the right thing to do, but you did not call.

Should not have

Should not have + past participle expresses that an action was wrong, unwise, unnecessary, or inappropriate.

You should not have called me.

This means calling me was not the right thing to do, and the context normally suggests that the call happened.

This distinction is important because adding not reverses the recommendation.

Should Not Have Does Not Always Express Regret

Although “should not have” often expresses regret or criticism, it can also describe an expected or inferred situation.

For example:

The train should not have arrived yet.

Here, the speaker is not necessarily criticizing the train. Instead, the speaker is saying that, according to expectations or the schedule, the train was not expected to have arrived by that time.

This illustrates why context matters when interpreting modal perfect constructions.

Common Mistakes

Mistake 1: Using “should haven’t”

Incorrect:

I should haven’t said that.

Correct:

I should not have said that.

Or:

I shouldn’t have said that.

The negative contraction belongs to should, not have. English does not normally form “should haven’t” in this construction.

Mistake 2: Using “should have not” as the default form

Less natural:

She should have not done that.

Preferred:

She should not have done that.

Mistake 3: Using “should not had”

Incorrect:

I should not had said that.

Correct:

I should not have said that.

After a modal verb such as should, the following verb is in its base form. Therefore, the correct sequence is should + not + have, not should + not + had.

Quick Comparison

Should not have
Correct and natural in standard English.

I should not have said that.

Shouldn’t have
Correct, natural, and especially common in conversation.

I shouldn’t have said that.

Should have not
Possible in rare emphatic or contrastive contexts, but generally awkward and not the preferred form.

I should have not said that.

Should haven’t
Incorrect.

I should haven’t said that.

The safest choice is “should not have” or its contraction, “shouldn’t have.”

How to Remember the Correct Form

A simple rule can help:

Put “not” after “should.”

Think of the pattern as:

should + not + have + past participle

Examples:

• should not have gone
• should not have eaten
• should not have called
• should not have waited
• should not have said
• should not have forgotten

If you are speaking informally, you can usually shorten it:

should not have → shouldn’t have

So:

I should not have done that.

becomes:

I shouldn’t have done that.

Summary

“Should not have” is the correct and natural choice for most situations. It follows the standard structure should + not + have + past participle and is commonly used to discuss past mistakes, regret, criticism, inappropriate actions, or things that should not have happened.

“Should have not” is much less common. Although it can appear in carefully constructed sentences where not receives special emphasis or contrast, it should not normally be used as an alternative to “should not have.”

For everyday and professional English, choose “should not have” or “shouldn’t have.”

FAQs

Is “should have not” grammatically correct?

It can occur in rare emphatic or contrastive constructions, but “should not have” is the normal and preferred form in standard English.

Is “should not have” correct?

Yes. “Should not have” is grammatically correct and commonly used to describe a past action that was wrong, unwise, unnecessary, or inappropriate.

Is “shouldn’t have” the same as “should not have”?

Yes. “Shouldn’t have” is the contracted form of “should not have.” It is particularly common in conversational English.

Which is correct, “I should have not done it” or “I should not have done it”?

“I should not have done it” is the natural and preferred form. “I should have not done it” is unusual and generally should be avoided unless there is a specific reason to emphasize not.

Can I say “should haven’t”?

No. “Should haven’t” is not the standard negative construction. Use “shouldn’t have” or “should not have.”

What does “should not have” mean?

It generally means that an action happened in the past but was considered wrong, unwise, unnecessary, or inappropriate.

What is the structure of “should not have”?

The structure is subject + should + not + have + past participle.

For example: “She should not have left early.”

Does “should not have” always express regret?

No. It often expresses regret or criticism, but it can also describe something that was not expected or logically should not have happened.

Is “should have not” ever used by native speakers?

Yes, it can occasionally occur, especially for emphasis or contrast. However, it is considerably less common and may sound awkward. “Should not have” is the safer choice.

What is the easiest way to remember the difference?

Remember that not normally follows the first modal or auxiliary verb. Since should comes first, use should not have, not should have not.