Direct translation vs Assumed or invented meaning
In many improv troupes, gibberish is used as a ‘gimmick’. The gibberish is not translated accurately, but becomes fodder for clever jokes based on attitude and gesture. Note in this video when an assumption happens and when there is direct communication.
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Until mastered, clear, short statements are easy to understand and a conversation will ensue after a few exchanges. As gibberish becomes ‘fluent’ much more can be expressed. The audience responds better to what they understood the gibberer to mean than if the interpreter made up a funny line based on misunderstanding.