During my cell meeting:
Me: I don't know... it's hard... some people just knows me too well.
Everyone: (Brief and silent look at each other)
Andrew: (Avoiding eye contact with me) Some people knows... ah ha ha
Me: (thinking: Ah... dang... I know, I know... it's meant to be 'Some people know', not 'knows') Oh, dang... alright alright..
'S' has got to be one of the most difficult thing to get right in the English grammar!