i-adjective
Only when written 長い
Describes physical length or spatial extent. Antonym: 短い (short).
Antonyms: 短い
この川はとても長い。
This river is very long.
彼は長い脚をしている。
He has long legs.
i-adjective
long (time); protracted; prolonged
Describes duration. Can be used for meetings, waits, lives, etc. 永い is sometimes preferred for very long or eternal durations.
長い間お待たせしました。
Sorry to have kept you waiting so long.
彼は長い人生を送った。
He lived a long life.