Examples
tā men他们bú不shì是zài在dǎ jià打架，ér shì而是zài在pái liàn排练xì jù戏剧。
他们不是在打架，而是在排练戏剧。
They aren't quarreling, but are rehearsing a play.
明天是运动会的排练，没有往常的课程。
Tomorrow there will be no normal lessons, in view of the athletic meet rehearsal.
最近一直在舞蹈排练，周五周六要演出啊。
Lately there have been constant dance rehearsals; Performances will be on Friday and Saturday.