1.比如family这个词:
Our family is in Beijing.我们家在北京。
Our family all like playing soccer.
我们家(的人)都喜欢踢足球。
2.又如:
Class Three is on the third floor.
三班在三楼。Class Three 这个集体在三楼,所以用is。
Class Three havefive English classes this week.
三班这周有5节英语课。只有学生才要上课,所以本句主语是“人”,故用have。