Plural of Measles
The final -s in “measles” can look plural, but standard dictionaries and grammar references treat the disease noun as uncountable/singular in grammar. There is no ordinary singular form “measle” for one case; count cases with a phrase such as “a case of measles.”
“Measles” is not an ordinary plural noun. In the disease sense it is uncountable and normally takes singular grammar: “measles is,” not “measles are.”
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| disease as a subject | measles is | Use singular agreement. |
| one occurrence | a case of measles | Count the case, not the disease noun. |
| several occurrences | several cases of measles | Pluralize “cases,” not “measles.” |
Quick tests
Plural-choice test
Are you using “measles” as the name of the disease?
If yes: Keep “measles” and use singular grammar where agreement is required.
If no: If you are counting occurrences, count “cases of measles.”
Caveat: This page addresses grammar only and does not provide diagnosis, prevention, or treatment advice.
Examples
Measles is highly contagious.
The disease noun takes singular agreement.
The school reported three cases of measles.
Occurrences are counted with “cases.”
A case of measles was confirmed.
The singular count unit is “case,” not “measle.”
Further guidance
Core difference
Treat “measles” as an uncountable disease name with singular agreement.
Fast Test
If you can replace the subject with “the disease,” singular agreement is the normal pattern.
Usage Boundary
Do not invent “measle” as a singular disease noun, and do not infer plural agreement from the final -s.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Nouns: singular and plural - Cambridge Grammar (opens in a new tab)Cambridge University Press · Cambridge Grammar lists thanks among nouns that are always plural in form, supporting plural-only number behavior.
- measles noun - Oxford Advanced Learner’s Dictionary (opens in a new tab)Oxford University Press · Oxford labels measles uncountable, supporting singular grammar despite the final -s.