Is it (shì bú shì)?

<1> Express inquiry and solicit opinions. For example: Is this the way to go? Is it you?

<2>Express doubt and disbelief. For example: Is that right?

<3>Every time, always. The first episode of "The Legacy of Xuanhe": "It can break people's brains at every turn, and the ax is coming." Yuan Zengrui's "A Flower·Buying a Smile" suite: "I'm afraid you are willing to tell me the truth, but don't you? Kong Jiaoren will give us some guidance." Chapter 1 of Yuan Gao Wenxiu's "Meeting the Emperor": "Is it necessary to ask for a hand model at every turn?" Chapter 64 of "A Dream of Red Mansions": "It's actually nothing to show him, but. I just don't think he wrote it properly for people to read."

<4>It is synonymous with "right or wrong".