I haven't been on HN for as long as most folks here. What is the policy on grammar correction? I know personally I want to be corrected if I make an error, but I don't think everybody feels that way...
For single posts, I'd say resist the impulse; it adds noise to the discussion and rarely helps anything. If the error is repeated, then it may be more helpful to correct.
Some spelling/grammar corrections are irrelevant, abusive, and inflammatory while others are instructive, helpful, and interesting. This community (to me) is more about the "hey, did you know that it's 'capital' except for when you're talking about the building, then it's 'capitol'" than the "STFU stupid, u can't even spell right"
Just curious so as to not rock the boat.