Used after a time, date, period, or event to mean before or not later than that reference point, as in 2010年以前 or 入学以前. With durations it may be translated with 'ago,' though ～前 is often the simpler everyday wording.
This building was built before 2010.
I do not remember much from before I entered school.
previously; before; the past; former times
Used as a noun or adverb for an earlier time or the past in general. Common in expressions such as 以前は, 以前の, 以前から, and 以前より.
I used to live in Kyoto before.
Please tell me your previous address.
He has become healthier than before.
I lived in this town before 2010.
There used to be a park here.
We've known each other for a long time.
I can't forget my former workplace.
以前 is a general, neutral word for 'before' or 'previously', while かねて specifically stresses that something has been true or intended since an earlier time and is more formal/written.
数年前 specifies roughly how long ago something happened, while 以前 is vaguer and just means "previously" without indicating a time span.
以前 is a more formal, neutral word for 'before' or 'previously', while 前々 is colloquial and stresses a vague stretch of time leading up to now.
以前 means 'before' or 'previously' and can refer to any point earlier than now, whereas 昔 implies a vaguer, more distant past.
以前 neutrally means 'before' without implying change, whereas 一頃 stresses a distinct past phase that has since ended.
以前 is a neutral, general term for 'before' or 'previously', whereas 一昔 carries a stronger sense of a bygone era that feels outdated compared to now.
以前 is a noun meaning 'before' or 'previous' and is often used as 以前に, while 先に is an adverb and cannot function as a noun.
以前 refers to some unspecified time in the past without implying recency, while この前 specifically points to a recent occasion.
以後 means 'after; from then on', the opposite time direction from 以前, which means 'before; previously'.
以前 means 'before' a point in time, the direct opposite of 以来's 'since/after' that point.
以前 means 'before' a reference point, the temporal opposite of その後, which means 'after' it.
以前 means 'before' a given point in time, the direct opposite of 以降 'from that point onward'.