字幕表 動画を再生する 英語字幕をプリント To sleep on it. To sleep on it means that you need a night to make a decision about something. For example: You may have been offered a job or you may have been offered an invitation to a party and you are not sure if you want to go or not; you may need one night to decide. So when somebody says, "Can I sleep on it?" they mean, can I have one evening to make my decision and I'll tell you tomorrow morning. For example: Do you want to come to the party? Umm... I'm not sure, can I sleep on it and I'll get back to you tomorrow? So, if you'd like to use this expression, sleep on it and think about a way that you can.