Employees who dress in a uniform every day might get bored.
Employees who dress a uniform every day might get bored.
Which one is grammatical and which one is more idiomatic?
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Sign up to join this communityEmployees who dress in a uniform every day might get bored.
Employees who dress a uniform every day might get bored.
Which one is grammatical and which one is more idiomatic?
Your first sentence is the only correct one.
"Uniform", when describing a set of standardised clothing, is a common noun and needs the indefinite article "a". You also need the preposition "in" to denote that the subject (the employees) is dressing in the uniform. To "dress a uniform" is certainly not idiomatic, but if it were to mean anything it would mean adding adornments to the uniform itself.
You could say that someone "dresses uniformly", but that is using an adverb form of the word "uniform" and does not necessarily refer to the kind of uniform worn by military, or certain workers etc.