1.
after this, from now on
From this point forward in time.
以後気をつけます。
I'll be careful from now on.
以後このようなことがないようにします。
I will make sure this doesn't happen again.
以後注意してください。
Please be careful from now on.
2.
after (a specific time/event)
Following a specified point in time or event.
3時以後は会議があります。
I have a meeting after 3 o'clock.
卒業以後、会っていない。
I haven't seen them since graduation.
4月以後に連絡します。
I'll contact you after April.
以後 indicates a time after a specified point.
USAGE:
- Can stand alone to mean "from now on"
- Can follow a time/event: X以後 (after X)
SIMILAR WORDS:
- 以後: after, from now on (formal)
- 以来: since, ever since (emphasizes continuation)
- 以降: from ~ onward (often written contexts)
- これから: from now (conversational)