Fossilized errors

Fossilized errors are those errors students make without even realizing it because they have made the error so many times in the past it has become a natural part of their speech. The error then becomes a habit and cannot be easily corrected. The only way to do so from teacher's part is close monitoring of individual students and emphasizing the error he or she is making. Only by keeping focus on the error, the student will become aware of it and try to correct himself/herself.

Speaking for myself, there are several instances of fossilized errors that I am aware of that are present in my speech and they can be traced to two issues - either I speak too quickly before I think about what I'm saying and therefore don't take the time to realize I'm making the mistake (that comes two seconds later), or it is subconscious.

The example of my subconscious fossilized error would be the use of the word concrete. I vividly remember the moment from my school years when my teacher stressed that this word has only one meaning in English and that would be the noun meaning (the building material), and therefore we can't use it in place of Czech "konkrétní" (=particular). He was actually making a case for a false friend. And even though I know now it to be not true, I have a block in my mind that prevents me from using the word concrete in its adjective form. Harsh, huh? Well, we all have our crosses to bear...

The examples of the "speaking before thinking" error are more numerous (especially in my case). I will provide two most recent (they're both from the last night actually):
For some reason, when I want to say that I am looking after someone or something, I always use the phrasal verb watch over instead. Though the meaning is somewhat related (look after = to take care of, watch over = to be in charge of), there is a slight difference. There's no deep insight here, it's just what I do...
The other example has to do with drinking - for some reason in place of the phrase bottoms up!, I use an expression to top up the glass instead (which is an utter nonsense, you don't top up a glass of a drink, you top up a battery when it's out of juice). You can see some resemblance between the phrases - both use the direction up and one speaks of a bottom while the other of a top, so if I had to look for a reason for this error, that would be my best educated guess. (This would make for a good study - the most common mix-ups in English phrases - but unfortunately I think this matter is so individual that it would be extremely difficult to arrive at any sort of generalization.)

This post and the examples of my faulty language were designed to give you an idea about what a fossilized error is and what form it can take. From my own experience I can say that old habits indeed die hard so teachers, be nice to your students, they may be very well doing their best and that one damn error slips away anyway.