매튜의 한국어 연습 블로그

There's nothing more embarrassing than having to ask where the bathroom is in broken Korean. If I had to pinpoint a particular moment when my face and pride first went out the window (first implies that my face has been lost many times which would be a correct assumption) it would be the awkward bathroom moment. I couldn't remember which one to say:
화장실 어디있어요?
화장실 어디예요?

To me, they both made sense. Now, I know the difference, but how can we differentiate them in English? How can I justify not using one over the other? First things first, a note about the subject. If the subject is an inanimate object, like, say the bathroom, it's fine to use both. If it's a person, you only have one option. Moving on with examples:

화장실 어디있어요? (o) Where is the restroom located? (shortened form)
화장실이 어디에 있어요? (o) Where is the restroom located? (grammatically correct)
화장실 어디예요? (o) Where is the restroom?

Both questions are asking the location of the restroom but the nuance is slightly different. Feel free to use both. Problem solved, right? Now, as for a person:

(다) 효연이 어디예요? (x) Where is the Hyoyeon?
(라) 효연이 어디있어요? (o) Where is Hyoyeon?

The first example doesn't make grammatical sense because 효연 is a person. I liken it to adding an unnecessary article like "the". I will say though that sometimes it can be heard in spoken language. It is a genuine mistake but then again, so is "That ain't right", "We be tough on'em" and "Git'er done".