"niedbalym potocznym jezykiem" Eva tu najlepiej okreslila.
I find the reactions of many native Poles to the phrases (gonna, dunno, kinda) to be rather strange. Poles, in general, take enormous pride in their language and its proper usage (Pr. Miodek is a great example). I have noticed how many native Poles may even judge others for the incorrect use of their own language.
With such an ingrained pride to speak properly, why the tolerance or even attraction for/to such poor use of language in English?
These phrases are not "cool". I can assure you I don't use them in my daily
life, I certainly would NEVER write them. All these phrases do is mark a person as having lazy speech or poor writing habits. I have a 6 year and a 9 year old, I do not let them use this kind of speech at home.
The southern United States (which includes Texas) have regional speech patterns/mannerisms which have made certain phrases "acceptable" over time. It does not mean these phrases are grammatically correct, it just means they have moved into the daily lexicon of native speakers in those areas.
When I meet a non-native speaker of English, I subconsciously judge their command of the language. If these phrases were to be spoken by a non-native, I would likely think he spent time among working class people (in factories or on the docks) and never received proper instruction.