If there's an AutoCorrect entry, whatever you typed is replaced with whatever sits in the entry. And the change occurs very, very quickly. Check Out Word's Built-in AutoCorrect Entries Start with a new document. Note the misspelling. I misspelled that word in a fourth-grade spelling bee, and never forgot it.
Word acommodates many misspellings.
Now type a space or a punctuation mark. Word changes acommodate to accommodate, as any, uh, accommodating program should. Let's go see why. Click Tools, then AutoCorrect. That's where Word picked up on the idea that it was supposed to swap out acommodate and swap in accommodate.