"I want to tell you something."
件 (jiàn) = item/component/classifier for events, things, clothes etc.
事 (shì) = matter/thing/item/work
情 (qíng) = feeling/emotion/passion/situation
事情 (shìqing) = affair/matter/thing
I guess this is used for non tangible things, contrary to 东西
告 (gào) = to say/to tell/to announce
诉 (sù) = to complain/to sue/to tell
告诉 (gàosu) = to tell/to inform