Which is proper?
I graduated high school
or
I graduated from high school
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.
Sign up to join this communityJacobIRR's link certainly goes over the rules well, but perhaps gets too snippy over right and wrong. It can't be overstated that language evolves with usage.
So if by proper you mean "following rapidly aging rules", graduated from. But if you mean "sounding correct to a native speaker", either one.