We are going to see a dramatic film, Era mio padre, so don't forget your handkerchief.

handkerchief 是由 hand（手）和 kerchief（头巾）组成的复合词，字面意思是"手巾"，指随身携带的小块方形布，用于擦汗、擦眼泪或擤鼻涕等用途。在观看感人电影时带手帕是为了擦眼泪。