What does 速い mean?
速い is a Japanese adjective meaning “fast, quick” in English. It can also be translated as “early, premature, as soon as ...” depending on context. It is written as 速い in kanji, はやい in hiragana, and hayai in romaji. This word is part of JLPT N5 vocabulary.
Example sentence
あれは世界で最も速い電車です。
That is the fastest train in the world.