I told you so; See? I told you!
Used when someone ignores your advice and ultimately fails; carries a tone of 'I told you so' or 'See what happened?'.
"I failed after all." "I told you so. Didn't I tell you?"
He said it was impossible, but she tried anyway and failed. I thought, 'I told you so.'
Variant with 事 instead of こと; less common but still seen.
A fixed phrase composed of それ (that), 見た (saw), こと (thing), and か (question marker), literally 'Did you see that thing?' It evolved into an idiomatic expression meaning 'I told you so'.