1. 是当真的：may as well 最好,不妨 | mean business 是当真的 | measure up to 符合,达到,够得上

2. 不是开玩笑：May West 救生衣 | mean business 不是开玩笑 | mean to say 你是说...

3. 说一不二：说一不二 Mean business. | 例句:When I give you my words, I do mean business. | 同义:说话算数 Keep one's word.

4. 是认真的：on business 因公,因事 | mean business 是认真的 | but for 倘没有,要不是