English grammar can be tricky, especially when it comes to modal verbs and negations. One common question learners face is: Should we say “should have not” or “should not have”? At first glance, both might look acceptable, but only one follows the standard rules of English grammar. In this article, we’ll break down the difference, explore why it matters, and show you how to use these phrases naturally in both writing and speaking. Should Have Not or Should Not Have.
Understanding the Basics: What Does “Should Have” Mean?
Before we look at the negative forms, it’s important to understand “should have.”
- “Should have” is a modal verb construction used to talk about a past action that didn’t happen, or one that did happen but wasn’t the best choice.
- It expresses regret, criticism, advice, or missed opportunities.
Examples:
- I should have studied more before the exam. (regret about a past mistake)
- She should have told me the truth. (criticism of a past action)
- You should have called your parents when you arrived. (advice about a missed action)
Notice that “should have” is always followed by a past participle verb (studied, told, called).
Read More: Rooting For You – Definition, Meaning, and Examples
The Correct Negative Form: “Should Not Have”
The standard negative construction is:
Subject + should not have + past participle
This is how native speakers naturally express regret or criticism of past actions.
Examples:
- I should not have eaten that second burrito. (regret)
- They should not have gone into that abandoned building. (criticism)
- You should not have told her the secret. (advice/criticism)
Why “Should Not Have” Is Correct
- Grammar rules: The negative adverb “not” must come after the first auxiliary verb (should) in English grammar.
- Clarity: This structure keeps the sentence smooth and natural, avoiding awkwardness.
- Usage frequency: According to Google Ngram Viewer, “should not have” is overwhelmingly more common than “should have not.”
The Awkward Alternative: “Should Have Not”
While you might sometimes see or hear “should have not,” it is unusual, nonstandard, and grammatically awkward.
Example:
- I should have not said that.
Although technically understandable, it disrupts natural word order in English. The negative adverb “not” feels misplaced because it interrupts the compound verb phrase.
When It Might Appear
- In poetry or older texts where word order is more flexible.
- For emphasis on “not” when a speaker wants to stress the negation.
Example:
- I should have not trusted him, but I did. (strong emphasis on “not”)
Still, most style guides recommend avoiding this phrasing in both formal and informal contexts.
Contractions: “Shouldn’t Have”
In everyday conversation, the contracted form is most common:
I shouldn’t have done that.
You shouldn’t have eaten the last slice of cake.
They shouldn’t have left so early.
This form sounds natural, fluent, and informal. It’s widely used in speech and casual writing like emails or text messages.
| Form | Example Sentence | Tone |
| Should not have | You should not have spoken like that in the meeting. | Formal, clear |
| Shouldn’t have | You shouldn’t have spoken like that in the meeting. | Natural, conversational |
| Should have not | You should have not spoken like that. | Awkward, avoided |
Expressing Regret and Criticism
The phrase is especially useful for talking about past mistakes.
- Regret: I shouldn’t have abandoned my studies when I had the chance.
- Criticism: He shouldn’t have been so careless with his work.
- Missed opportunity: We shouldn’t have missed that meeting; it was important.
Key point: This structure allows you to look back on past actions and judge them as mistakes, bad choices, or missed chances.
Real-Life Examples in Context
Let’s apply these phrases to situations you’ve probably experienced:
- Food regret: I shouldn’t have eaten the last slice of cake. Someone else wanted it.
- Work mistake: She shouldn’t have ignored the warning from her boss.
- School scenario: I shouldn’t have skipped so many classes; now I’m far behind.
- Relationships: He shouldn’t have said those harsh words to her.
Notice how each sentence refers to a past action that already happened but is now judged negatively.
Why Word Order Matters in English
English word order is more rigid than some languages. Negative adverbs like “not” usually come right after the first auxiliary verb:
I should not have gone.
I should have not gone.
Although the second option is understandable, it feels unnatural and clumsy.
General Rule:
- Place “not” after the first auxiliary verb.
- Don’t split “should” and “have” unless you’re deliberately emphasizing.
Usage Data: What Google Ngram Shows
If you compare the phrases on Google Ngram Viewer, you’ll see:
- “Should not have” dominates in modern English.
- “Should have not” is almost never used, except in rare or archaic contexts.
This shows that native speakers overwhelmingly prefer the standard pattern, making it the safe and correct choice for learners.
Synonym and Alternative Expressions
Instead of using “should not have,” you can sometimes rephrase with other expressions:
| Expression | Example | Tone |
| Ought not to have | You ought not to have lied to her. | Formal, rare |
| Had better not have | You’d better not have touched my things. | Informal, warning |
| Was wrong to | He was wrong to say that. | Neutral, simple |
| Regret + verb-ing | I regret leaving so early. | Direct, emotional |
Common Mistakes to Avoid
- I should haven’t done it. (incorrect contraction—never used)
- I should have not done it. (awkward placement)
- He should not has done it. (wrong verb form)
Correct: I shouldn’t have done it.
Memory Tips for Learners
Here are a few tricks to remember the correct form:
- Think of “not” as a shadow: It always follows the first helper verb.
- Use contractions in speech: shouldn’t have is smooth and natural.
- Practice with regrets: Write 5 sentences about past mistakes using “should not have.”
Example practice:
- I shouldn’t have stayed up so late last night.
- We shouldn’t have ignored the traffic rules.
FAQs
Is “should have not” grammatically correct?
Not in standard English. It’s awkward and rare, though you may see it used for emphasis in unusual contexts.
What is the correct phrase: “should not have” or “should have not”?
The correct phrase is “should not have” (or its contraction “shouldn’t have”).
Why can’t we split “should” and “have” with “not”?
Because grammar rules place “not” after the first auxiliary verb. Splitting the phrase causes awkwardness.
Can I use “shouldn’t have” in formal writing?
Yes, but in very formal texts, it’s better to use the full form “should not have.”
What’s a good synonym for “should not have”?
You can say “was wrong to,” “ought not to have,” or “regret + verb-ing.”
Conclusion
The difference between “should not have” and “should have not” might seem small, but in English, word order matters a lot. The standard, natural, and correct phrase is always “should not have” (or its contraction “shouldn’t have”). The alternative “should have not” sounds awkward, is almost never used, and should be avoided in writing and speech.
If you want your English to sound fluent and natural, stick with:
I shouldn’t have done it.
You should not have said that.
By mastering this simple structure, you’ll avoid one of the most common grammar pitfalls and express yourself with clarity, confidence, and correctness.
