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Usage and Grammar
Q. In the following sentence, I would rather omit all but the first article to make the sentence more concise: “It can be a professor, a boss, an adviser, or a coach.” But can I do this even though an “a” would not be used before “adviser”? In other words, would “a professor, boss, adviser, or coach” be correct?
A. Think of the n in “an” as a temporary intervention that’s used only to prevent the glottal stop that would result from saying “a adviser” out loud (or in one’s head). It’s purely a concession to speech, having no grammatical significance; “an” means exactly the same thing as “a.” If you decide to omit the article, there’s no need to worry about that n.
And you can drop the articles in a series after the first, provided they’re all the same type—either definite (the) or indefinite (a, an)—and provided the sentence remains clear without them (as is the case with your example).