I do not agree at all when you say: Don't expect to learn much by asking others to make corrections.

Being corrected by native english speakers is very useful for me. If I do not understand a correction, I just ask in the answers section, I look for some examples on the internet or, I just try to use the correction I have been made in another notebook, and I see if I have understood the way it should be used.

It is true that a teacher is a great guide and if you can afford it, it will be, undoubtedly a good help! But I am very pleased with the corrections and explanations that I have been given so far and I am grateful to those who take time to make corrections expecting nothing in return.

However, I want to express my disappointment with those who expect someone teaching them for free. Teaching is a job and it means spending time preparing a class and of course an "inside" knowledge of the language itself. 

But at this point, I am looking for real language practice. I have had spent enough years studying grammar with teachers (some of them better than others) and I have realized that once you have the basic knowledge, the key is practice.

I have done many courses for free (because of my profession) and they were amazingly good! I do not mean free things are not worth just because of the fact that they cost nothing. What I mean, is that many people want to have someone teaching them English for free and not giving them anything in return (such as teaching them their own language or paying a fee).

I am happy with what I am doing because I have come across to people who are (educated!) native speakers of English, with whom I practice regularly. In return, I help them with Spanish, and yes! I am also an educated woman, speaking Spanish, though.

It is very generous of you to teach people expecting nothing in return. I guess (as you have mentioned above) that the fact of teaching itself might be rewarding for you. Good for you and for you "students"!

Laura, I teach them for free.  I do this for dozens of reasons I won't go into here.  There is a common belief that if a thing is free, it has no value.  Many feel that the more you pay, the better quality you will get.  It is a normal opinion.  It is sometimes true and sometimes not.  We say, "You can pay as much as you want."

As a native speaker of English and an educated man, I can tell you that the average literacy rate in the US has been dropping for 30 years.  Asking random passers-by to correct and advise you on such a complex and confusing language as English might not lead to the results you are seeking.  If you have no basis of comparison, as most here do not, you might not see any problem.

If you're happy with what you're doing, keep doing it.  :-)