Two Senses
1. By means of / via — a medium or intermediary.
- 友人を通じて知り合いました。(We met through a friend.)
2. Throughout a period — the whole span, without a break.
- 一年を通じて温暖です。(It's mild all year round.)
を通じて vs を通して
Near-interchangeable, with a slight lean:
| Pattern | Lean |
|---|---|
| を通じて | the medium matters; more common for spans of time |
| を通して | the speaker's own active effort in going through it |
経験を通して学んだ feels slightly more personal than を通じて. Neither is wrong in most sentences.
Against によって
Both cover "by means of", and the split is what kind of means:
| Pattern | Means |
|---|---|
| によって | a method or an agent |
| を通じて | a channel you pass through |
A person you go via takes を通じて; a person who performs the action takes によって.
Register
Formal. In speech, で or から often does the job for sense 1.
