かい

「かい」 is a sentence-final question marker, 「か」 plus 「い」, and sounds friendlier and gentler than a bare 「か」. It is mostly heard from men in casual talk, or from an older person to a younger one, a parent to a child, or between acquaintances. The voice rises at the end: 「準備はできたかい？」 (Are you ready?), 「痛いかい？」 (Does it hurt?).

•Related forms: 「かい」 leans male or older-to-younger and is warm; with a question word the form is 「だい」: 「どうしたんだい？」 (What's wrong?); 「の？」 is used by everyone and is very common among young people; 「かしら」 is used by women.

•Never use it with a boss, client or elder. It is very casual speech between people who know each other.