Have you ever written “what happen” and wondered whether it should actually be “what happens”? This is a common English grammar question because the correct form depends on the sentence structure and the tense.
In most present-tense questions and statements, “what happens” is the grammatically correct form when what refers to a singular event or situation. However, “what happen” can be correct in certain structures, especially when another subject or auxiliary verb controls the verb.
For example:
- “What happens next?” ✅
- “What happened yesterday?” ✅
- “What will happen tomorrow?” ✅
- “What happen next?” ❌ in standard English
In everyday conversations, people often use phrases such as “What happens?”, “What happened?”, and “What will happen?” to ask about events, results, or situations.
Updated for 2026, this guide explains what happen vs. what happens, shows how the forms work, and provides practical examples for students, writers, social media users, and English learners.
1. What Is “What Happen”?
The simple meaning
“What happen” and “what happens” are related to the verb happen, which means to take place or occur.
The main problem is usually subject-verb agreement.
In standard present-tense English, when what represents a singular event or situation, the verb generally takes the singular form:
What happens?
Example:
“What happens when you press this button?”
The question asks what occurs after the button is pressed.
Is “what happen” always wrong?
No. “What happen” can appear correctly when the verb is controlled by another grammatical structure.
For example:
“What did happen?”
Here, did carries the past tense, so the main verb stays in its base form: happen.
Similarly:
“What will happen?”
The modal will is followed by the base form happen.
Therefore, you should not simply memorize that “what happen” is always wrong. Instead, learn to look at the helping verb and sentence structure.
2. What Happens vs. What Happen
“What happens?” is the normal present-tense question
Use happens when asking about something that occurs generally, regularly, or in the present.
Example:
“What happens if I miss the deadline?”
The question asks about the result of missing the deadline.
“What happen?” is usually incorrect by itself
If you are asking a simple present-tense question, say:
“What happens?”
not:
“What happen?”
The -s is required because the verb agrees with the singular subject represented by what in this structure.
3. How “What Happens” Works
“Happen” means “take place”
The verb happen describes an event or situation occurring.
Example:
“Accidents happen.”
Here, happen is used with the plural subject accidents.
But with a singular subject:
“An accident happens.”
The verb becomes happens.
Questions with “what”
When what functions as the subject of a present-tense question, use the appropriate verb form.
Example:
“What happens next?”
Here, what represents the thing or event that occurs next.
Common structure
A useful pattern is:
What + happens + …?
Examples:
- What happens next?
- What happens if we leave early?
- What happens after the meeting?
- What happens when the battery dies?
4. When “What Happen” Is Correct
This is where many learners become confused.
After “did”
Use the base verb after did.
Correct:
“What did happen?”
Incorrect:
“What did happened?”
The word did already marks the past tense, so the main verb stays in its base form.
After “will”
Use happen after will.
Correct:
“What will happen next?”
Incorrect:
“What will happens next?”
Modal verbs such as will are followed by the base form.
After other modal verbs
The same rule applies to modal verbs such as:
- can
- could
- may
- might
- should
- would
- must
Examples:
“What could happen?”
“What might happen?”
“What should happen next?”
In each sentence, happen remains in the base form.
In certain plural-subject structures
If what is not the grammatical subject and the actual subject is plural, the base form can also be appropriate.
Example:
“What things happen during the experiment?”
Here, things is plural, so happen agrees with the plural subject.
5. What Happens vs. What Happened vs. What Will Happen
These forms refer to different times.
| Expression | Time | Example |
|---|---|---|
| What happens? | Present/general | What happens if it rains? |
| What happened? | Past | What happened yesterday? |
| What will happen? | Future | What will happen tomorrow? |
| What is happening? | Happening now | What is happening outside? |
| What has happened? | Past with present relevance | What has happened here? |
| What did happen? | Past emphasis | What did happen after that? |
Learning these patterns makes the difference much easier.
6. Examples of “What Happen” and Related Forms in Everyday Life
In everyday conversations, people often use these questions when they want to understand an event, result, problem, or future possibility.
1. What happens next?
This asks about the next event in a process or story.
2. What happens if I press this button?
The speaker wants to know the result of an action.
3. What happens when the power goes out?
This asks about the consequences of losing electricity.
4. What happened yesterday?
This asks about a completed past event.
5. What happened to your phone?
The speaker wants to know what caused a problem with the phone.
6. What will happen tomorrow?
This asks about a future event.
7. What is happening outside?
The speaker wants information about something occurring now.
8. What has happened here?
The speaker is asking about a past event that has a connection to the present.
9. What did happen after the meeting?
The speaker uses did to emphasize the past question.
10. What could happen if we wait?
The speaker asks about a possible future result.
7. 40 Examples Related to “What Happen”
Here are practical examples that show the correct forms and meanings.
Present-tense examples
1. What happens next?
This asks about the next event.
2. What happens if I make a mistake?
The speaker asks about the result of making a mistake.
3. What happens when the class ends?
This asks about what normally occurs afterward.
4. What happens during the test?
The question asks about the process or events during the test.
5. What happens after dinner?
This asks what usually or currently comes afterward.
6. What happens when you restart the computer?
The speaker wants to know the result of restarting it.
7. What happens if it rains?
The speaker asks about a possible result.
8. What happens at the end of the movie?
This asks about the ending.
9. What happens when the battery is empty?
The speaker asks what occurs when the battery has no power.
10. What happens if we arrive late?
The question asks about the consequences of being late.
Past-tense examples
11. What happened?
This asks about a past event.
12. What happened yesterday?
The question refers specifically to yesterday.
13. What happened at school?
The speaker wants information about a past school event.
14. What happened to your car?
The speaker asks why something happened to the car.
15. What happened after lunch?
The question asks about an event that followed lunch.
16. What happened during the meeting?
The speaker wants a summary of the meeting.
17. What happened when you arrived?
The speaker asks about events at the time of arrival.
18. What happened last night?
The question concerns a previous night.
19. What happened to the package?
The speaker wants to know where the package went or what went wrong.
20. What happened after the power went out?
This asks about events following a past power failure.
Future examples
21. What will happen next?
This asks about a future event.
22. What will happen if we cancel?
The speaker asks about a future consequence.
23. What will happen tomorrow?
The speaker asks about tomorrow’s events.
24. What will happen after the exam?
This asks what is expected afterward.
25. What will happen if we miss the bus?
The speaker wants to know the likely consequence.
26. What could happen if we ignore the problem?
This asks about a possible consequence.
27. What might happen next?
The speaker asks about a possible future event.
28. What should happen after this step?
The speaker asks what is expected to occur.
29. What would happen if we changed the plan?
This describes a hypothetical situation.
30. What can happen during a storm?
This asks about possible events or conditions.
Present continuous and perfect examples
31. What is happening?
This asks what is occurring now.
32. What is happening outside?
The speaker wants information about something happening nearby.
33. What is happening with the project?
The speaker asks about the current status of a project.
34. What has happened?
The speaker asks about an event that has already occurred.
35. What has happened to the computer?
The speaker wants to know what caused a current problem.
36. What has happened since yesterday?
This asks about changes from the past until now.
Questions with “did”
37. What did happen?
The speaker emphasizes the question about a past event.
38. What did happen after you left?
The speaker wants details about what occurred afterward.
39. What did happen to the plan?
The speaker asks what caused the plan to change or fail.
40. What did happen at the end?
The speaker wants to know the final event.
8. “What Happen” vs. Related Concepts
Understanding related forms is useful because many grammar mistakes happen when learners confuse tense and helping verbs.
| Form | Correct? | Example |
|---|---|---|
| What happens? | ✅ | What happens next? |
| What happen? | Usually ❌ alone | What happen next? |
| What happened? | ✅ | What happened yesterday? |
| What will happen? | ✅ | What will happen tomorrow? |
| What did happen? | ✅ | What did happen? |
| What did happened? | ❌ | Did already marks past tense |
| What will happens? | ❌ | Will requires base verb |
| What is happening? | ✅ | What is happening now? |
The key grammar rule
When a helping verb such as did, will, can, could, may, might, should, would, or must comes before the main verb, use the base form:
did + happen
will + happen
could + happen
might + happen
But without such a helping verb, present-tense agreement determines the form:
What happens?
9. How to Use “What Happens” Correctly
Step 1: Identify the time
Ask yourself whether you are talking about:
- Present
- Past
- Future
- Something happening now
- A past event connected to the present
Step 2: Check for a helping verb
If you have did, use happen.
Did + happen
If you have will, use happen.
Will + happen
If you are asking a simple present question without a helping verb, use happens.
What + happens?
Step 3: Think about whether the question is general or specific
For a general process:
“What happens when you restart the device?”
For a completed event:
“What happened when you restarted the device?”
For a future possibility:
“What will happen when you restart the device?”
10. Common Mistakes People Make With “What Happen”
Mistake 1: Writing “What happen?” for a simple present question
Incorrect:
“What happen next?”
Correct:
“What happens next?”
Mistake 2: Adding -s after “did”
Incorrect:
“What did happens?”
Correct:
“What did happen?”
After did, use the base form.
Mistake 3: Adding -s after “will”
Incorrect:
“What will happens?”
Correct:
“What will happen?”
Modal verbs require the base form.
Mistake 4: Confusing “happen” and “happened”
Use happened for a simple past question.
Example:
“What happened?”
Do not use:
“What happen yesterday?”
Mistake 5: Confusing “what happens” with “what is happening”
What happens? can refer to a general event or process.
What is happening? usually asks about something occurring right now.
Compare:
“What happens when you press the button?”
This asks about the general result.
“What is happening?”
This asks about the current situation.
11. “What Happens” in Essays and Academic Writing
The phrase what happens can be useful in academic writing when explaining processes, results, or cause-and-effect relationships.
Example
“The experiment demonstrates what happens when water reaches its boiling point.”
The phrase introduces the process being explained.
Another example:
“The study examines what happens when students receive immediate feedback.”
Here, the phrase introduces a result or process.
For students, learning this structure can make explanations clearer and more natural.
12. “What Happens” in Creative Writing
Writers can use what happens to create curiosity or introduce an event.
Example
“Nobody knew what happens when the door opens at midnight.”
This creates suspense.
A writer might also use:
“What happens next is something she never expected.”
This sentence creates anticipation and encourages the reader to continue.
From real-life writing experience, questions involving what happens can be effective because they naturally create curiosity and make readers want to discover the answer.
13. “What Happens” in Captions and Social Media
The phrase is also common in modern online writing.
Caption examples
“What happens next? 👀”
This creates suspense.
“You never know what happens behind the scenes.”
This encourages curiosity.
“What happens when you finally choose yourself?”
This creates a reflective or motivational tone.
“Nobody knows what happens after the final bell.”
This can create mystery or anticipation.
Short questions like these work well on social media because they encourage readers to stop, think, and respond.
14. Famous or Popular Expressions With “Happen”
The verb happen appears in several common English expressions.
“What happens next?”
A common phrase used when discussing stories, movies, events, or processes.
“Things happen.”
This expression can mean that unexpected events are simply part of life.
“Accidents happen.”
A common expression used to say that mistakes or accidents are sometimes unavoidable.
“Whatever happens”
This means regardless of what occurs.
Example:
“Whatever happens, stay calm.”
“What happens if…?”
This structure introduces a possible condition and its result.
Example:
“What happens if I forget my password?”
15. What Happen vs. What Happens: Easy Memory Trick
Use this simple rule:
No helping verb + present → happens
“What happens?”
Did + base verb → happen
“What did happen?”
Will + base verb → happen
“What will happen?”
Is + -ing → happening
“What is happening?”
Has + past participle → happened
“What has happened?”
This gives you a useful pattern:
happens → happen → happening → happened
The correct form depends on the tense and sentence structure.
16. Suggested Internal Links
For an English grammar website, consider adding internal links to related topics such as:
- What Happened vs. What Happens
- Happen or Happened: Which Is Correct?
- What Is Happening Meaning and Usage
- Did Happen or Did Happened: Grammar Guide
- Will Happen or Will Happens: Which Is Correct?
- Present Simple Tense Rules
- Simple Past Tense Examples
- Helping Verbs in English
- Subject-Verb Agreement Explained
- Happens vs. Occurs: Difference and Usage
These related articles can help readers understand the verb happen from several grammatical angles.
17. Frequently Asked Questions
Is “what happen” grammatically correct?
By itself, “what happen?” is generally incorrect as a simple present-tense question. The usual form is “What happens?”
However, happen is correct after helping verbs such as did and will.
Is it “what happens” or “what happen”?
For a simple present question, use “what happens.”
Example:
“What happens next?”
But use “what happen” after a modal or auxiliary structure such as:
“What will happen?”
Is “What did happen?” correct?
Yes. “What did happen?” is grammatically correct. The word did carries the past tense, so the main verb stays in its base form, happen.
Is “What will happen?” correct?
Yes. “What will happen?” is the correct future form.
Do not say:
“What will happens?”
What is the difference between “what happens” and “what happened”?
What happens generally refers to the present, a repeated event, or a general result.
“What happens if I press this button?”
What happened refers to a completed event in the past.
“What happened after you pressed the button?”
18. Quick Answer: What Happen or What Happens?
If you need a quick answer, remember:
“What happens?” is normally correct for a simple present-tense question.
Use “happen” after helping verbs:
- What did happen?
- What will happen?
- What can happen?
- What might happen?
- What should happen?
Use “happened” for a simple past question:
- What happened?
Use “is happening” for something occurring now:
- What is happening?
The key is not to memorize one form as always correct or incorrect. Instead, look at the tense and helping verb in the sentence.
Conclusion
The difference between “what happen” and “what happens” is mainly a matter of grammar and sentence structure. For a simple present-tense question, “What happens?” is the standard form. When a helping verb such as did or will comes before the verb, use the base form happen.
The easiest patterns to remember are:
What happens?
What happened?
What will happen?
What did happen?
What is happening?
Once you understand these patterns, you can use happen confidently in conversations, essays, stories, captions, social media posts, and everyday English. Practice creating a few questions of your own, and choosing the correct form will quickly become natural.
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