1.
one letter; one document; one copy
A counter expression for one letter, document, email, or written communication. The counter 通 is used for letters, emails, and documents.
Uses the counter 通, which counts letters, emails, documents, and written communications. The reading of 一 changes to いっ before つ due to sound change (促音便).
Counting patterns
- 一通: one letter/document
- 二通: two
- 三通: three
- 四通: four
- 五通: five
- 何通: how many letters/documents?
Note: 一通り is a different word with a different reading, meaning "generally; the whole thing; one way." Do not confuse the two.