A:I assume you know about the latest goings-on with Hessington oil.
B:I wouldn't be much of a partner if I didn't.
A:Now they've decided to take on Ava Hessington personally.
B:Who is they?
A:The U.S. government.
These are lines cited from Suits.
Why did this B say who is they instead of who are they?
Best Answer
Use-mention distinction
This is an example of the use-mention distinction. In the sentence "Who is they [sic].", "they" isn't being used as a pronoun, but instead is being used a word. That is, it's referring back to the use of the word "they" in the previous sentence ("Now they've decided to take on Ava Hessington personally.")
Notice in that sentence by A the "they" takes the plural form of the verb ("they are"/"they're"). This is always the case with "they" when it's used as a pronoun; it's always gramatically plural, even when it's used to refer to a single person. (Which, despite moaning by some pedants, is a perfectly valid English construct.)
In the sentence by B ("Who is they?"), the "they" isn't being used as a pronoun, but is being used to refer to the word "they" that was used by A in the previous sentence. The convention in English is that when you have this sort of "mention" case - where you use a word as a word as opposed to using it for its meaning - you should place that word in quotes or italics. So the closed captioner should really have rendered it as
or
The fact that they didn't is either due to limitations of the closed captioning system (for example an inability of the system they were using to represent quotes or italics), or simply because the captioner wasn't aware it was needed.
Note that the quotes/italics here aren't being used as "scare quotes" or as some sort of marking of incorrect usage, but as a literal quote of the word itself. As such, the speaker wouldn't actually make an air quote gesture, but probably would subtly emphasize the "they", either by saying it in a slightly different tone or pausing slightly before saying it.