又当又立 英语怎么说

"又当又立"在英语中可以翻译为 "to act as if one were an authority" 或 "to behave imperiously". 这个短语来源于中国文化，用来形容一个人自作主张，专横跋扈。

例句：

He always acts as if he were an authority on the subject, but in reality he knows very little. 他总是又当又立，自认为是这个领域的权威，但实际上他知道的很少。
She behaves imperiously, expecting everyone to do as she says. 她专横跋扈，指望每个人都听她的话。