Luggage is an uncount noun. You can have a piece of luggage or some luggage but you cannot have 'a luggage' or 'some luggages'. In British English, people normally use luggage when they are talking about everything that travellers carry. Baggage is a more technical word and is used for example when discussing airports or travel insurance. In American English, luggage refers to empty bags and suitcases and baggage refers to bags and suitcases with their contents. Both British and American speakers can refer to everything that travellers carry as their bags. American speakers can also call an individual suitcase a bag.

luggage为不可数名词，可以说 a piece of luggage 或 some luggage，但不能说 a luggage 或 some luggages。英国英语一般用luggage来指旅行者携带的所有东西，而 baggage 则是一个较为专业的用语，用于有关机场或旅行保险等话题中。在美国英语中，luggage 指空的包和手提箱，而baggage 则指包和手提箱及其中的物品。英国英语和美国英语中均可以用 bags 来指旅行者携带的所有东西。美国英语还可以用 bag 来指单个手提箱。