I am afraid, these days, that the level of spelling and grammar in general use is not what it was when I was at school (a long time ago). I think that automatic spelling and grammar functions in word processing and DTP programmes have led to some real 'howlers' but I think people seem to be less able to spell as a result of not having to 'learn' the English language in the same way that it was taught for generations. My OH's a teacher and she can't understand where it all starts to break down ... she thinks it may be that kids don't READ as much as they used to and that doesn't help.
As for the automatic word filling function on
iphones and the like ... well, you have to be really careful ...
If you want a good laugh:
http://www.damnyouautocorrect.com/