Here is a passage about learning a foreign language. Outside of class, the most natural way of finding out if you are making mistakes is from other people's responses. If the mistakes are too serious, your listeners will be asking you all the time what you mean. If they are not so serious, then people may be asking you whether you said such and such. That will tell you how close you are to speaking "cogently". Of course, there are other times when it is important to have errors pointed out. Your class assignments  are probably marked in this way, in which case you need to spend time going over them to take advantage of the individual feedback. In some classes the teacher gets better and better at grammar because she does all the corrections, but the students make slow progress if, when an assignment is returned, they quickly stuff it into their folders without looking. You are the person who should be connecting your error, even if the marker has signaled them, when you look at them; there are some steps to work through. One distinction that has been made about learners' language is this. You make mistakes about rules that you already know but you make errors about points you haven't learned yet. In other words, you can find your own mistakes, but not your errors. First, make sure you understand what you have written or said, or your correction will simply be another stab at the right answer. Next, decide on the best way of practicing the correct form. Would it help you to write out the sentence once more? Can you make up another similar sentence? Then you could test yourself in a few days time to see whether you have remembered the right form, anyone can get it right immediately after being told. He challenge is to remember it and apply it later. Which of the following might be the most important to work through your mistakes?
Keeping the right form in mind and using it later. Writing out the sentence once more. Learning your mistakes by heart. Correcting your mistakes and writing down the teacher's words.