| specialize(verb, concentrate) |
| be a party to(verb, take, play, join, aid) |
| engage(verb, take, play, join, aid) |
| enter into(verb, expression, phrasal verb, take, play) |
| go in for(verb, expression, idiom, phrasal verb, practice) |
| pursue(verb, practice, train) |
| sit in(verb, expression, phrasal verb, take, play) |
| sit in on(verb, expression, idiom, phrasal verb, take) |
| tune in(verb, expression, phrasal verb, take, play) |
| aid(verb, play, join, perform, engage) |
| associate with(verb, expression, phrasal verb, play, join) |
| be a participant(verb, play, join, aid, perform) |
| be in on(verb, take, receive, contribute, participate) |
| chip in(verb, expression, phrasal verb, play, join) |
| come in(verb, expression, phrasal verb, play, join) |
| compete(verb, play, join, aid, perform) |
| concur(verb, play, join, aid, perform) |
| confine |
| consume(verb, take, receive, contribute, participate) |
| cooperate(verb, play, join, aid, perform) |