Chinese phrase
不是〜，是〜 bú shì 〜 shì 〜
Meaning
not ___ but ___
When to use it
It says something is not one thing but is another. It often corrects or clarifies information in a direct way.
Example dialogue
这道菜里有鸡肉吗？ zhè dào cài lǐ yǒu jī ròu ma
Does this dish have chicken in it?
这道菜不是鸡肉，是牛肉。 zhè dào cài bú shì jī ròu shì niú ròu
This dish doesn't contain chicken; it has beef.