Do most non-native Spanish speakers use proper grammar?
There is no definite answer to this question.
Depending on who is speaking, and where they learn the language, their language use could vary greatly.
There is a better possibility for formal learners to make less grammatical errors, but this does not mean they are more competent within a language.
Non-native speakers of language language will make mistakes from time to time.
I would say that even native speakers will make mistakes.
In my experience teaching Spanish, I find that it is more important that a learner is making sense overall, than to make no mistakes.
In conclusion, I would not generalize so much.
You must consider the learners, and where their education is coming from.
College students and middle school students are both "non-native speakers", their competency is really dependent on how they are learning, and how they are practicing.
I hope this helps!
I would say most people speak a language how they are taught and most non-native speakers learn in a classroom where they are taught "proper grammar.
" Having said that, for native English speakers at least, Spanish grammar, especially verbs, can be HARD, so we are often, for example, confusing the verbs ser and estar and the prepositions por and para and various tenses.
So while non-native speakers may have the inclination to use correct grammar–which means they'll use less slang–they will probably make more grammatical mistakes than native speakers.
Especially when starting out.
Both native and non-native speakers of every language vary in their command of grammar.
My guess is that among non-native speakers of any language, there are more people with limited training/practice than fluent speakers.
So most non- native speakers probably don't use perfect grammar.
I would add that fear of making a mistake prevents language learners from getting the practice they need.
It's much more effective to have a shot of tequila or pisco or aguardiente and let fly than to stay silent for fear of making a mistake.
I tend to agree with Nicholas DeTore.
Non-native speakers who really want to learn any language well, end up becoming very much aware of the grammar of their target language and being able to have better command of it than native speakers.
And usually, non-native speakers are also better able to explain why a grammar point is correct or incorrect.