Excuse me. I'm afraid you've made a mistake. This is my luggage.
对不起。您恐怕弄错了。这是我的行李。
Oh, I'm very sorry. The two suitcases look almost the same.
哦，真抱歉。这两个皮箱看起来差不多一模一样。
That's all right. Just be carefull next time.
没关系，下次注意点。
I will.
我会的。
luggage n.行李
suitcase n.(旅行用)小提箱，衣箱