Final answer:
Conventions is the trait that refers to the use of proper spelling, punctuation, capitalization, and grammar.
Step-by-step explanation:
The trait that refers to the use of proper spelling, punctuation, capitalization, and grammar is conventions. Conventions are the rules and norms of language that help ensure effective communication. They include things like using commas, periods, and capital letters in the right places, as well as using correct spelling.
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