why does iphone autocorrect correctly spelled words

Apple is not here. Please submit your feature request to Apple at this link: http://www.apple.com/feedback

Can you confirm you Language & Region settings, as well as what are your Input sources in Keyboard preferences?

Wanted to ensure that you do not have non-English input source selected as primary, which could possibly cause the issue.

I'm noticing this too, it's very infuriating. Especially with "well" and "we'll". It makes me angry because getting we'll and well right can't be that hard. If I could just make it fully manual for these two words I'd be happy.

This is not due to language settings. It is a nasty bug in iOS that for some reason Apple seems to be ignoring. Autocorrect is not working. It changes commas to exclamation points, 'corrects' perfectly good words to rare terms that no one would use... It's broken. Apple, PLEASE fix this!

Go to settings>general>reset>keyboard layout

What happens is that you type a word, and it replaces it with a word you've used more commonly, I know, I hate it too, but do what I showed and it should help!

Oh, they're here. Lurking...