を通じて / を通して【をつうじて / をとおして】

をつうじて通じて and をとおして通して follow a noun and mean "through": the person, medium or experience something passes through to happen. Both belong to writing and careful speech.

Before a noun, the forms are をつうじて通じての and をとおした通した.

Throughout a period

After a stretch of time, the same pair means "throughout": the whole period, with no break.

を通じて or を通して

In most sentences either works. を通して puts more weight on someone deliberately using a person or channel to get something done, so it suits a go-between you choose. を通じて is more neutral and suits a channel things simply travel along, like a network or the media.

Passing through a place

For physically going through a place, use the verb とおる通る with を. を通して and を通じて are for means and periods, not for routes.

• × トンネルを通して町に入った → トンネルを通って町に入った