たの

expression

sentence-ending particle expressing emotion, admiration, or emphasis

Abbreviation of ～ていたの. Used at the end of a sentence, often in casual speech, to add emotional coloring, admiration, or emphasis. Common in feminine or childlike speech, but also used more broadly in informal contexts.

See also: わ

• 昨日きのう、すごく楽たのしかったの。

  It was really fun yesterday, you know.

• もう食たべちゃったの？

  You already ate it? (with surprise/emphasis)