Speak Setswana proper or not at all

What I find strange is that nobody ever seems to be particularly concerned with expressions like "I'm gonna kill you" instead of "I'm going to kill you". This, to me is hardly surprising. I have heard slang being spoken from the time I was a primary school pupil to this day even by people well-schooled in English. Is colloquial Setswana any different? I am not for one moment down playing the importance of speaking any particular language in its purest form. On the contrary I take the position that the use of English and Setswana words, interchangeably has become a fact of life which we must simply recognize as a habit of speaking given the fact that we now live in a global village.

Trying to coin words to describe things for which we do not have Setswana words in the hope that this will impress language purists that we love our Setswana language no less than English or other languages only make us sound or look ridiculous.