this may help you : http://french.about.com/od/grammar/a/savoirconnaitre.htm
I wrote "I am acquainted with the boy" and was marked wrong. The mouse-over translation of connais includes "am acquainted with" as a legitimate translation! What the heck?
Moreover, the "correction" said "I am familiar with the boy" is acceptable. Well then why isn't "am familiar with" on the mouse-over translation? These sorts of things really irritate me as a user!