Sentenceっけ
Usage
っけ is a question marker. It is used only in very casual conversation. Note that after the non-past forms of verbs, adjectives and -ない, んだ must be used before っけ.
Examples
この漢字って、どう読むんだっけ?
This Kanji, how do you read it?
マイクさん、今、どこの大学に留学してたっけ?
Mike, now, at which university will you study abroad?