Learning how to write these verbs with s or es is one of the first essential steps for anyone studying English grammar. Because of that, whether you are a beginner student, an English language teacher, or a professional looking to polish your writing, mastering third-person singular verb endings helps you communicate clearly and correctly. In the present simple tense, verbs change form when the subject is he, she, or it, and knowing exactly when to add -s versus -es can prevent common mistakes that often confuse both native and non-native speakers.
Understanding the Basics of Verbs with S or Es
English verbs generally stay the same for most subjects: I work, you work, we work, they work. On the flip side, when the subject shifts to a third-person singular noun or pronoun—such as he, she, it, or a singular name like Maria—the verb usually requires an ending. This is a core part of
People argue about this. Here's where I land on it.
This is a core part of mastering third‑person singular forms, and the rule set can be broken down into clear, easy‑to‑apply patterns.
1. The default – add ‑s
For the vast majority of verbs, simply tack an ‑s onto the infinitive.
work → works play → plays watch → watches
2. When the verb ends in a sibilant sound
If the verb’s ending is -s, ‑ss, ‑sh, ‑ch, ‑x, ‑z, or -o, the pronunciation demands an extra syllable, so we add ‑es instead of just ‑s.
fix → fixes brush → brushes watch → watches go → goes
3. Consonant‑plus‑y → change to ‑ies
A verb that ends in a consonant followed by ‑y normally changes the y to ‑ies when the subject is third‑person singular.
carry → carries study → studies reply → replies
4. Verbs already ending in ‑es
Some verbs already carry the ‑es ending in the base form (e.g., has, does, says). In these cases the ‑s is added directly, not ‑es again.
has → has does → does says → says
5. Irregular third‑person singular forms
A handful of verbs are completely irregular and do not follow the patterns above. Memorising these few exceptions prevents surprise in everyday usage:
| Base verb | Third‑person singular |
|---|---|
| be | is |
| have | has |
| do | does |
| go | goes |
| see | sees |
| eat | eats |
| run | runs |
6. Quick checklist for writers
- Identify the subject: he, she, it, or a singular noun.
- Look at the verb’s ending.
- Apply the appropriate rule (‑s, ‑es, ‑ies, or recall the irregular form).
- Read the sentence aloud; the extra syllable in ‑es forms should be audible.
7. Common pitfalls and how to avoid them
- Dropping the extra e after s: “He fix the car” → correct is “He fixes the car.” Remember that ‑s alone is insufficient when the verb ends in a sibilant sound.
- Forgetting the ‑ies transformation: “She study math” → “She studies math.” The y must be replaced.
- Applying the rule to plural subjects: “They watch movies” (no ‑s), but “He watches movies.” Keep the singular rule separate from plural forms.
8. Practice makes perfect
