get down to brass tacks／get down to cases
begin the most important work or business；get started on the most important thing to talk about or know 讨论实质问题；谈论正经事
The men talked about little things and then got down to brass tacks．这些人先谈了一些鸡毛蒜皮的小事，然后就言归正传了。
You have talked about everything under the sun；now you'd better get down to brass tacks．你们已经天南海北乱扯了许多，现在最好要谈正经的了。