I notice "do you copy that?" is used in movies to ask for confirmation in telephone/interphone conversation.

I only know copy means make things duplicated, so why use it in "do you copy that"? Is there a history about it?


4 Answers 4


This comes from military, amateur and CB radio communication

"Do you copy?" or "Copy that!" is likely from when a message had to be written down to be shown to a superior officer


Some words with specialized meanings are used in radio communication throughout the English-speaking world, and in international radio communications, where English is the lingua franca.

Affirmative — Yes
Negative — No
Reading you Five / Loud and clear — I understand what you say 5x5.
Over — I have finished talking and I am listening for your reply. Short for "Over to you."
Out — I have finished talking to you and do not expect a reply.
Clear — I have finished talking to you and will be shutting my radio off.
Roger — Information received/understood.
Copy — Mostly used to acknowledge received information. [May also mean Repeat back to me the information I just gave you. ed.]
Wilco — Will comply (after receiving new directions).
Go ahead or Send your traffic — Send your transmission.
Say again — Please repeat your last message (Repeat is not used as it is a specific command when calling for artillery fire)
Break — Signals a pause during a long transmission to open the channel for other transmissions, especially for allowing any potential emergency traffic to get through.
Break-Break — Signals to all listeners on the frequency, the message to follow is priority.


Copy probably originally referred to writing or typing a received message, but now has is essentially the same as 'Reading you ...'.

  • 4
    copy that! lol 哈哈…… Commented May 6, 2011 at 6:56
  • I'm not sure that you can attribute it all to CB radio communication; as mentioned in the wikipedia article "by the military, in civil aviation, police and fire dispatching systems, citizens' band radio (CB), etc."
    – Matt Wilko
    Commented May 6, 2011 at 9:06
  • 2
    @Matt - I think it was through CB radio that Radio procedure made it into the common vernacular. Before CB radio, only those in the uniformed services and civil aviation would have had need of it, but the explosion of CB radio in the 70's would have brought it to the general populace.
    – Mark Booth
    Commented May 6, 2011 at 10:32
  • With modern CB language, the last one break-break, I've often heard as breaker-breaker.
    – Orbling
    Commented May 6, 2011 at 11:43
  • 3
    I am an amateur radio operator (ham). It is more correct to say these terms came from military and amateur radio use, both of which developed more or less simultaneously. CB came much later, and CB operators do not use most of those terms. They created their own vernacular like 'breaker 1-9', 'you got yer ears on?', and other '10' signals such as 10-4 which I believe are more associated with police and fire services.
    – adj7388
    Commented Nov 18, 2013 at 18:46

This phrase originated with Morse Code. You can make a perfect copy of the sounds you hear onto a sheet of paper.

The phrase undoubtedly came into popular use from Amateur (ham) Radio users who moved into CB radio. Amateur Radio users discuss copying traffic as part of their hobby. http://www.arrl.org/appendix-b-nts-methods-and-practices-guidelines

Amateur radio has a list of short-hand symbols that are used to quickly transfer information through Morse Code (and later were used over-the-air). One of the most popular is QSL which means either Do you copy or I copy. Amateur Radio users first started sending QSL cards to acknowledge successful contacts around 1920.


  • This seems plausible, but I don't understand the subject quite well enough to tell whether it's accurate. Could you please expand your answer a bit to lay out the connection between “copying” Morse code (which I didn't understand from the Wikipedia article) and “I copy”? Commented Sep 5, 2013 at 0:04
  • Thanks for your comment: I updated it. Better?
    – dcaswell
    Commented Sep 5, 2013 at 0:20
  • I think so. I take it then that QSL means literally, “Did you get that down on paper?” but because radio operators can often “copy” code mentally, it evolved to mean “Did you understand that?” Commented Sep 5, 2013 at 0:30

Two years later, I find another wrinkle in this tapestry.

http://en.wikipedia.org/wiki/Procedure_word mentions that Copy has a specifically different use from Roger in Maritime VHF. Copy is used to mean "I heard that as well" when a message between two stations includes information that has some sort of importance to another station. For example, Boat A tells Boat B that there's debris in the water and gives GPS coordinates. Boat B responds "Roger." Boat C breaks in and responds "Copy that."

This explanation of the distinction seems to make sense. It also makes sense that these two meanings would run together over time, especially in more informal radio traffic.


I have no idea but it occurred to me that "Copy" sounds a lot like "Capiche" which means understand in Italian. I thought perhaps it could have come from that.


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