Well, I have the same problem with a couple of adult students. There is nothing I can do, they keep repeating the same mistakes even if I point them out, and even if I tell them to correct themselves... Sorry Susan... but I guess this is something related to their lack of self esteem when trying to speak a foreign language.
One day, my English Inspector, on an Extension Course to all the teachers in the region told us that we should "wash the students with English". What she meant was to expose them to as many resources as possible: books, audio/visual material, extensive reading, intensive reading, not too much grammar, in short, let them hear or read what the right patterns are, and then it will happen someday that they will also produce correct language.
I use to record dialogues, for example, leaving time between one sentence and the other for the students to repeat whenever they can. They bring with them their pendrives and copy my dialogues, with a printed page so that they can follow, hear and repeat. It works!!! Also songs, or jokes, and I always insist that they speak only English even if they don't know all the words. They must try to explain what they mean, without asking "How do you say..... (in their mother tongue) ?"
I hope it helps, nilusha.
Syl's English Corner - Learn English and Have Funhttp://www.ginnegar.0catch.com