other N3 common politewritten
以後 — after / from then on / hereafter
以後 ・ いご
Meaning
- after (a point in time) / from then on / hereafter — everything from a given moment onward
Key sentence
三時以後は家にいます。
I'll be home after three o'clock.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Time noun | N(time) + 以後 | 卒業以後 / 来週以後 |
| On its own (adverb) | 以後、… ('from now on, …') | 以後、気をつけます。 |
Examples
会議は十時以後に始まる。
The meeting starts after ten o'clock.
以後、このようなミスがないようにします。
From now on, I'll make sure there are no mistakes like this.
When you can't use it
- 以後 includes the point named and everything after it, and is formal. In casual speech 〜のあとで or 〜から is far more natural (三時のあとで, not 三時以後, when chatting).
Easily confused with
以降 Nearly synonymous as 'from ~ onward,' but 以降 is purely a range marker tied to a stated time (四月以降). 以後 can also stand alone as 'henceforth' with a corrective tone (以後気をつけます = 'I'll be careful from now on'), which 以降 cannot. 〜以来 以来 looks back from a past starting point up to the present ('ever since'), stressing the continuous stretch. 以後 simply marks everything after a point, with no 'up to now' nuance. 〜あと(で) あとで is the everyday 'after ~ing' for ordering two events. 以後 is a formal time-boundary ('from this point onward') rather than 'after doing something.'
See 以後 in real sentences
Jengo shows 以後 the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Advanced Japanese Grammar.