"Is it a chair?" is also accepted as correct.
How does Hungarian signify plural? I noticed that "szék" is "chair" and "chairs" in English. Is this just one odd word, or are there no plurals in Hungarian?
Chair -> Szék Chairs -> Székek
With nouns, you form the plural with -k (or -ek/-ok/-ak/-ök depending on the word). I'm not so sure about exceptions, though.