使用复印机的英语对话通常包括以下步骤和要点：

询问如何操作

A: "Excuse me, can you tell me how to use this copy machine？"

电源和插头

B: "First, put this plug in the socket over there. Then, switch the power on."

放置原件

B: "Lift the cover and place the original face down."

选择纸张尺寸

B: "And then close the cover and select the size of paper."

设置复印数量

B: "Press the button of the number of copies you need."

开始复印

B: "Finally, press the start button."

确认理解

A: "Are you clear？"

B: "Yes, I understand now."

其他问题

A: "Do you know how to do it now？"

B: "Yes, thank you so much."

以上步骤和对话内容可以帮助用户了解如何使用复印机。