Translation guide
In Japanese, the word for 'stair' depends on whether you mean a single step, a flight of stairs, or stairs as a structure. The most common word is 階段 (kaidan), which refers to stairs as a whole. For a single step, use 段 (dan).
Referring to a set of steps that connect two levels, such as in a building or outdoors.
The standard word for stairs or a staircase. Use this in most situations.
階段を上ってください。
Please go up the stairs.
この階段は急ですね。
These stairs are steep, aren't they?
Can also be used with counters to specify flights of stairs.
一階段上ると、右側にあります。
Go up one flight of stairs, and it's on the right.
Referring to one individual step in a staircase.
Means a step or stair. Often used with counters or in compound words.
この階段は何段ありますか？
How many steps does this staircase have?
一段一段ゆっくり上ってください。
Please go up one step at a time slowly.
Literally 'stepping step', used in technical or architectural contexts.
Describing types of stairs or stair-related objects.
Used in compounds to specify types of stairs.
非常階段はあちらです。
The emergency stairs are over there.
この螺旋階段は美しいですね。
This spiral staircase is beautiful, isn't it?
Also used in compounds for step-like things.
階段 (kaidan) refers to the whole staircase, while 段 (dan) refers to a single step. Using 階段 when you mean a single step can cause confusion.
この階段は10段あります。
This staircase has 10 steps.
Use the counter 段 (だん) to count steps: 一段 (いちだん), 二段 (にだん), etc. For flights of stairs, you can use 一階段 (ひとかいだん), but it's less common; usually you just say 階段を上る/下りる (go up/down the stairs).
Adjust the height of the steps.
There's a step here, so please be careful.