well i from my own experience not many chinese refer to the different Chinese arts as kung fu. They would ask like "you do Hung Ga Kuen?" and not Hung Ga Gung Fu. They would ask you if you practice Gung Fu since the most common association with that word is with the martial arts. But what was previously said is correct, there is no Kung Fu system and anything involving a skill can be called Kung fu, whether it be in killing someone or in washing dishes.
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"you're going to work till you wish you were dead and then keep going.."
-Sgt Slaughter