funktionieren:to be working (as intended) [as in: functioning]

gehen: to be working (as intended) [as in: functioning] [also means: to walk, of course!]

Examples and Usage Notes Mnemonics

Examples and Usage Notes:

Der Kopierer funktioniert/geht nicht. The copier isn't working.
Wie funktioniert das? How does that [machine or device] work?
Wie geht das? How do you do that?
--"Geht das?"
--"Ja, das geht."
--"Can that be done?"
--"Yes, that works."
Das geht so: Erst muß man... It works like this: First, one has to...
--"Hat das Experiment geklappt?"
--"Did the experiment work?"
--"Hast du das Attachment bekommen?" 
--"Ja, das hat geklappt."
--"Did you get the attachment?" 
--"Yes, that worked." 
[Here, "klappen" is used because it's not so much a question of whether the computer is running properly as of whether the attempt to send an attachment (something you tried to do) worked.]