In Japanese language we use the Japanese word "何故(なぜ - naze)" for the English word "why". And also we use "どうして(doushite)" or "なぜなの(nazenano)" for "why". These "どうして(doushite)" or "なぜなの(nazenano)" are mainly used by female. And "何故なんだ(nazenanda)" or "どうしてなんだ(doushitenanda)" have same meaning but mainly used by men.
The following are some example sentences in which these Japanese words are used.
- 何故あなたは日本語を習っているのですか(naze anataha nihongowo naratte irunodesuka)? The meaning of this sentence is "Why are you learning Japanese language?"
- お前がそれを話さないのは何故なんだ(omaega sorewo hanasanainoha nazenanda)? - Why don't you tell about that?
The second Japanese character image "なぜ" is hiragana for "why".
The third Japanese character image "ナゼ" is katakana for "why".