I can't imagine myself deteriorating in my English standard to the extent that I write "at el" instead of "et al" while instructing others, nor that I write "then" in place of "than" (no I don't think it's an typo because he repeated the mistake twice in the same place). I've seen a lot of people who are involved in other activities that did not require writing in English most of the time thus the decrement in standards, but I really really really hope that I will NOT be one of them when I start working. :S I guess that would mean more work on my part trying to maintain my English standard (or even improve) :)