1. being well versed (in), being well acquainted (with), being familiar (with), having a thorough knowledge (of), being an authority (on)
2. (a boy's) first ejaculation, spermarche, semenarche
1. at (place, time), in, on, during
2. to (direction, state), toward, into
3. for (purpose)
4. because of (reason), for, with
5. by, from
6. as (i.e. in the role of)
7. per, in, for, a (e.g. "once a month")
8. and, in addition to
9. if, although
1. to do, to carry out, to perform
2. to cause to become, to make (into), to turn (into)
3. to serve as, to act as, to work as
4. to wear (clothes, a facial expression, etc.)
5. to judge as being, to view as being, to think of as, to treat as, to use...