If we really want to split hair, I’ll say a mistakes is something done incorrectly, because of not knowing how to do it correctly, or simply misunderstanding the proper method or procedure. On the other hand, an error is the result of oversight or carelessness which is different from a mistake. These are subtle distinctions that requires different remedies.
In English, we learn the grammar rules which we try to apply conscientiously in our writing or speech. Depending on the individual, his background, learning environment and the level of enthusiasm, progress and the kinds of errors experienced vary from person to person. The ones I pointed out are the ones I personally experienced and noticed among the follow Chinese learners. The problems which Hao mentioned are much deeper than the “common” variety in my view. and are more of the grammatical variety. Observations from various English forums have convinced me that preposition, article and participle usage are difficulties commonly shared by almost all learners. Unless one is exposed to a completely English speaking environment and immersed in complete usage, meaning using English only, eliminating these problems seems almost impossible. It’s only when we use and expose to natural English long enough, that we will get a hang of what is or sounds correct.
If I may apply the same comparison in ballroom dancing to learning English, I ‘d like to confess that I have the same problem in ballroom dancing as the English learners do in English. My dance instructor taught us different variations and forms of a dance each week and we’ve practiced and practiced in the class which seemed fine at the time. A week went by and we went to the next session, the variation and moves which we’ve learned and practiced were partially forgotten or executed incorrectly. But if we review and practice each night for 15-21 minutes, we can feel the difference and do much better as a result of repetitions, exposure and practice. The point of this is, if we really want to be good at something, we have to keep pushing forward until we reach a level of “second nature”. I understand, what works for Tom may not work for Ted. But it worked for me. This is only my opinion but I hope it helps.