From Longman Dictionary of Contemporary EnglishI told you soI told you soWARNused when you have warned someone about a possible danger that has now happened and they have ignored your warning I suppose you’ve come to say ‘I told you so.’ → tell
Examples from the Corpus
I told you so• I could never work with a man like that and I told him so.• I wouldn't have blamed him if he'd walked away and I told him so.• There; I told you so.• To sum up: I told you so.• True it is that Ewan Beg thought he had killed his dallta - for I told him so.• What matters is that we lived like writers, and that I told them so.• I didn't like his mood. I told her so, but she just laughed.• I was not disappointed. I told myself so, firmly, several times. 