"Actually, Twitter forces you to think about what you tweet, otherwise it won’t fit into those pesky 140 characters. I think that the primary cause of deterioration of language skills (or spelling skills, which isn’t the same — especially in English), is that we’re exposed to so much more text *that hasn’t been checked and corrected professionally*. In the olden days, publishing something took effort, and so you took pains to do it right. If you weren’t good at spelling or language, you made sure you got a corrector, or you picked another job. Nowadays, everybody and their dog can e-mail, send text messages, tweet. In general, I’d say that that is a good thing. The consequence, though, is that we’re exposed to language of a much greater variety in skill level. And since we learn by example, we also tend to adopt idioms that would not have been acceptable in days of yore... :-)"
- Martijn Coppoolse