Collective nouns refer to groups of people usually. Our choice of singular or plural verb form often depends on whether we are thinking of the group as an
impersonal unit(in which case we use the
singular verb- and relative pronoun
which) or as a
collection of individuals (in which case we use the
plural verb form - and relative pronoun
who). Compare the following:
The team
who are playing this weekend includes neither of the new signings
The team
which lies third from the bottom of the league will also be relegated this year
http://www.bbc.co.uk/worldservice/le...rnitv358.shtml