I would say this is a decent sentence, but maybe something long these lines would be more grammatically correct (yes I know I probably put a knife in grammar with this opening sentence):
"If students do not learn the sentence structure, they may make many mistakes while conversing with native speakers of English."
That's my thoughts, anyone have any corrections?
Though if your going to converse with someone from the USA (I cannot speak for England) even broken butchered English will work with a good chunk of us (the better you are at speaking it, the more people will understand without thinking on it, but that's a given in all languages). There are many different grammatical structures in the USA for English, those of us in farming areas are more likely to use 2 or more negatives in a sentence, and those in places of downtown, and poor income will be more likely to use slang (combinations of 2 or more words used to either sound unique, save ones breath, or just cause).... Well this is just through my personal observations anyways.
I wish you luck in your endeavors.