Meaning and Usage
The suffix ～階 (～かい) is used to count floors or stories of a building. It attaches to numbers to indicate which floor is being referred to, such as 一階 (first floor), 二階 (second floor), and so on.
Common Contexts
This counter is very common in everyday conversation when talking about buildings, offices, apartments, or any multi-story structure. It is often used with elevators, directions, or locations within a building.
Collocations and Patterns
- ～階建て (～かいだて): describes how many stories a building has (e.g., 三階建て means a three-story building).
- ～階にある (～かいにある): indicates something is located on a certain floor.
- ～階で止まる (～かいでとまる): used when an elevator or similar stops on a specific floor.
Register and Politeness
This counter is neutral and used in both casual and formal contexts. It is a basic and essential vocabulary item for daily life.
Common Mistakes
Learners sometimes confuse ～階 with ～回 (also read かい), which counts occurrences or times. Remember that ～階 specifically counts floors, while ～回 counts frequency or number of times.