means "prior to" an event: the rest of the sentence says what is
done in advance of it, usually to prepare. It goes after a noun or a verb in
the dictionary form.
means the same and is a little less
stiff, and
modifies a noun.
、。
Prior to the opening, there will be a greeting from the chairman.
、。
Prior to the construction, an information session was held for residents.
、。
Before starting the match, the two teams shook hands.
。
A press conference was held ahead of the launch.
The noun before に先立ち is the event still to come, and the main clause is
what happens first.
に先立ち or 前に
is the everyday "before" and works for anything. に先立ち belongs to
announcements, ceremonies, business and the news, and it needs an event of
some weight: a meeting, a launch, an election. Everyday actions take 前に.
。
I had a coffee before the meeting.
、。
Prior to the meeting, the materials were handed out.
- × 寝るに先立ち、歯を磨いた → 寝る前に、歯を磨いた