I think overall it's a good thing. You just shouldn't let it come to extremes... For people i know in real life i always prefer meeting them in person rather then IM. I think my Dutch grammar would be better without IM because i talk to much English online. But, my English has only got better
. As for a social life... i always (try to) put that in the first place, i wll never prefer to stay at home and chat while friends go out.
Other then that, IM is great and saves allot of time and money (allot of IM messages would have been phonecalls or SMS otherwise). And IM can eventually create reallife friendships too
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