This happens because most of the time you need an explicit "it" in English, you can simply omit "it" and leave "it" implicit in Japanese.
Manga: Kobayashi-san Chi no Meidoragon 小林さんちのメイドラゴン (Chapter 2, トールと出会い)
- Context: Kobayashi 小林 sees a dragon girl in maid clothes.
- meido fuku...
メイド服・・・
Maid clothes... - yume? yahari yume ka?
夢?やはり夢か?
[Is it a] dream? As I thought, [is it a] dream?
But let me explain more about each use of "it" in English and what's done in Japanese instead.