Since my sister occasionally emails me with a list of errors I've made, I'll be careful here. Although I do try to catch everything, I don't always. The key word is "try." When I read a hub that is full of careless spelling and grammatical errors, I vote it down. If there are a few, I ignore them because I know everyone can overlook a few things. I have a friend on hub pages who tells me things I've screwed up and I tell her, but that's a different matter. I would not dream of offering criticism to someone I don't even know, not only because it might offend them but also because their work is not my responsibility. My sister is a huge help because she takes my stuff apart when she has time and her criticism is awesome. I'm so bad about placement of prepositions and she nails me on it. Everyone should be so lucky to have a former English teacher read through their work. Anyway, I agree with Arlene, I would do nothing -- except vote it down if it's riddled with errors.