You scratch my back and I'll scratch yours. / If you scratch my back, I'll scratch yours. / I'll scratch your back if you scratch mine.
- I'll grab the box on the top shelf if you will creep under the table and pick up my pen. You scratch my back, and I'll scratch yours. (如果你願意爬到桌子下面撿我的筆，我也願意把架子最上面的箱子拿下來。你幫我，我也幫你，投桃報李)
- I do have some information you might be interested in, but what can you offer me in return? You scratch my back and I'll scratch yours. (我真的有一些你可能感興趣的資訊，但你要拿什麼來回報呢？投桃報李啊！)