Definition: to take legal action against someone and try to get money from them because they have harmed you Level: C1
他威胁要起诉该报社诽谤。
He threatened to ___sue the newspaper for libel.
如果我收不到退款，我将不得不起诉这家公司。
If I don't receive a refund, I will have to ___sue the company.
该公司决定起诉其前高管违反合同。
The corporation decided to ___sue its former executive for breach of contract.
