"stairs" 與 "staircases" 有何分別?

stair (countable noun) 樓梯的一級, (階梯的某)一級 = one of the steps in a set of stairs

stairs (plural noun) (樓層之間的) 樓梯 = a series of steps that go from one level or floor to another.

staircase (singular noun) 樓梯 (包括扶手,欄杆) = a set of stairs inside a building including the posts and the rails (banisters) that are fixed at the sides.

banister (noun) (樓梯的〕欄杆, 扶手 = the posts and the rail which you can hold for support when going up or down stairs.

最大差異 stairs 不包括欄杆, 扶手.
許多時, staircase 與 stairs (相同解”樓梯”) 可互換使用, 不理有無欄杆, 扶手

a flight of stairs = 一段楼梯 (無 a flight of staircases 這個 phrase)

A stair is one of a succession of steps leading from one floor to another; stairs means either the steps of staircases or a series or 'flights' of such steps.



2014-06-27 04:45:22 補充：
Jenkin:

"但外國住宅(例如三層的村屋或...裏面的樓梯只會叫(stairs)"
~ 你這個 statement 是錯

美國波士頓, 不論 town houses, bungalows, 有些屋出售賣點是有 spiral staircase

http://wickedlocalbostonhomes.com/2013/09/boston-real-estate/charlestown-triplex-boasts-signature-spiral-staircase/

2014-06-27 09:00:57 補充：
stairs 和 staircases 同是 plural

staircases 是多過 one set of steps, 例如前後門有, 合計 two staircases
stairs 多過一級樓梯, 可能 2, 3, 4 ..etc.stairs,
stairs 並且可指 one set of steps

stairs通常是指上落的梯級
staircase是指建築結構的整個樓梯內部= 梯間

stairs通常意義是指走上落的梯級
staircase是指建築結構上設置的樓梯

香港見到的大都是大廈樓宇或商場公眾的樓梯或走火通道的樓梯(staircase)，但外國住宅(例如三層的村屋或兩層的別墅式平房裏面的樓梯只會叫(stairs)

希望這種簡單的分幫助你解決大部份寫作的取捨。

He ran down the stairs in the fire escape staircase when he heard the fire alarm.