Earning a degree, certificate, or even just taking a few classes to acquire new skills can get you back in the game.
When you have a series like the compound subject of this sentence, each item in the series needs to be the same and follow logically from the same point in the sentence. In this sentence, the items are wildly different:
- a degree (article, noun—follows from Earning)
- certificate (noun—follows from a)
- even just taking a few classes ... (noun phrase built around a gerund—follows from the beginning of the sentence)
There are several ways you could fix the sentence. For instance, you could make the series parallel:
Earning a degree, earning a certificate, or even just taking a few classes to acquire new skills can get you back in the game.
Or you could do what I did—turn the third item (which is so different) into a complementary element (and thereby avoid a lot of repetition):
Earning a degree or a certificate, or even just taking a few classes to acquire new skills, can get you back in the game.
An interesting note on this parallelism rule: Some sticklers feel that it should apply to articles. For instance, they would not allow "A dog and aardvark danced awkwardly on the lawn"—because aardvark can't follow from A. It needs the article an, so those sticklers (and I am one of them) prefer "A dog and an aardvark danced awkwardly on the lawn."
I prefer to repeat the article in every case.
Read "4 Signs You're Ready for a Career Change."