Two common pet peeves among language editors relate to incorrect noun pluralization, most often meaning that “s” or “es” is unnecessarily added to the end of a noun. The first type of error is unnecessary pluralization of a noun used as an adjective, also known as an attributive noun. For example,
- Nanoparticle structures (correct)
- Nanoparticles structures (incorrect)
- Five-week-old mice (correct)
- Five-weeks-old mice (incorrect)
Generally, an attributive noun should not be plural, even if the noun that is being modified (“structures” and “mice” in the examples above) is plural; exceptions to this rule (e.g., “sports games”) are infrequent.
The second type of error is incorrect pluralization of certain commonly used mass nouns, or nouns that do not have a plural form because they are uncountable. As an example,
- Bcl-2 and caspase expression (correct)
- Bcl-2 and caspase expressions (incorrect)
In scientific writing, the term “expression” is considered as both singular and plural, particularly when referring to protein or gene expression. To emphasize its use as a plural term, “expression levels” or similar phrasing may be used instead. Note that “expressions” serves as a count noun in other, frequently non-technical contexts, such as when referring to “facial expressions.”
Other uncountable nouns often used in technical writing that should not be pluralized are “research” and “evidence.” However, because both terms can be used as verbs as well as nouns, “researches” and “evidences” may be appropriate as singular verbs. Note that as a result, spellcheck may not detect errors in usage. Plural count nouns that may be used instead include “studies” (instead of “researches” as a noun) and “lines of evidence,” “pieces of evidence,” “studies,” “results,” or “findings,” depending on the context (instead of “evidences” as a noun).
This editing tip has hopefully illuminated common instances of and ways to avoid incorrect noun pluralization. Please email us with any questions or comments. Best of luck with your writing!