JLPT N1
～もの(だ)
used to ~; would often ~ (nostalgia about the past)
Structure / Usage
Verb (た-form) + ものだ / ものだった
Example Sentences
子供の頃はよくこの川で遊んだものだ。
When I was a child, I used to often play at this river.
学生時代は夜遅くまで勉強したものだった。
In my student days, I would often study until late at night.