
Why Do Verbs Ending in “S” Matter?
Let’s paint a picture. You’re in your first English conversation, you want to say “He run fast”, and the person you’re talking to gives you a confused look… like you just said “He pineapple fast.”
Yep. That tiny “s” you forgot? It makes a big difference.
Understanding verbs ending in s is essential for beginner and intermediate learners because it shows you’re using the present simple tense correctly. It’s not just grammar nerd stuff—it’s about sounding natural and avoiding the classic mistakes English learners make daily.
In this post, you’ll learn:
- The basic rules for adding “s” to verbs
- Some sneaky exceptions
- The most common mistakes to avoid
- A mini quiz so you can check your skills
Whether you’re writing a sentence, chatting with friends, or just trying not to embarrass yourself in front of your English teacher, these tips will save you.
The Rules: When Do Verbs End in “S”?

Present Simple + Third Person Singular = “S”
Here’s the simple rule: In the present simple tense, when the subject is he, she, or it, you add an s to the verb. That’s it.
Basic Examples
- He walks to school.
- She eats breakfast at 8.
- It rains a lot in October.
You are not walking. He is. So he gets an “s.” That’s grammar justice.
Spelling Variations
Verb Ending | Rule | Example |
---|---|---|
-o, -ch, -sh, -x, -ss | Add -es | go → goes, watch → watches |
Consonant + y | Change to -ies | study → studies |
Vowel + y | Just add -s | play → plays |
For more sentence structures like this, check out our guide on Understanding Simple Sentences.
Where You Use These Forms

- Daily routines: “He brushes his teeth.”
- Facts: “Water boils at 100°C.”
- Scheduled events: “The train leaves at 9.”
If you want a broader explanation of this tense, the British Council’s grammar guide has some fantastic beginner-friendly material.
Exceptions and Common Mistakes
When NOT to Add “S”
English wouldn’t be English without a few chaos sprinkles.
Plural Subjects
Plural subjects don’t take “s” on the verb:
- They run every day.
- My parents work late.
Modal Verbs
Modal verbs ignore the “s”:
- She can swim.
- He should study.
Still confused about how auxiliary verbs work with conditionals? Try our conditional sentences guide.
Common Learner Mistakes
Incorrect | Correct |
---|---|
She go to school. | She goes to school. |
He watch TV. | He watches TV. |
The cat like tuna. | The cat likes tuna. ✅ |
Tips to Avoid Mistakes

Use the “he test”:
Can you replace the subject with “he”?
If yes → Add that “s.”
For a deeper dive into verb forms, Cambridge English has a clear breakdown with more examples.
Interactive Quiz: Fill in the Blanks
Let’s see if your brain was actually working while reading all that.

Fill in the blanks using the correct form of the verb in parentheses.
- She __________ (watch) Netflix every night.
- He __________ (like) pizza with pineapple.
- It __________ (rain) a lot in April.
- My friend __________ (study) at university.
- The dog __________ (bark) at the mailman.
- He __________ (go) to the gym after work.
- She __________ (teach) math.
- My parents __________ (live) in Spain.
- They __________ (play) football every weekend.
- He __________ (have) a big car.
Answer Key
- watches
- likes
- rains
- studies
- barks
- goes
- teaches
- live
- play
- has
🧠 Pro tip: Say the sentences out loud. If it sounds like a toddler wrote it, something’s missing. Probably the “s.”
Conclusion: Mastering Verbs Ending in “S”
We covered:
- When to add “s” (present simple + third person singular)
- When not to (plural subjects, modal verbs)
- Classic mistakes to avoid
- A practice quiz to seal the deal
Now don’t just scroll past and forget it—practice. Get it wrong a few times. Then get it right. That’s how language works.
Want more grammar help?
Browse all our grammar articles or take a look at our guide to the future tense to strengthen your grammar even further.