Why does duolingo show "gonna" as correction of "going to" in an answer example?
I am taking the Spanish reverse tree and made a typo in one of the words and was very surprised to see that in the correct answer duolingo corrected my typo word then also substituted my "going to" with the "word" "gonna" in its correct answer. I always thought of gonna as slang and if I wrote it down in school work it would be marked wrong. According to Merriam Webster http://www.learnersdictionary.com/definition/gonna. "Learner's definition of GONNA — used in writing to represent the sound of the phrase going to when it is spoken quickly I'm gonna [=going to] get you if it's the last thing I do! ◊ The pronunciation represented by gonna is common in informal speech. The written form should be avoided except when trying to represent or record such speech. — " I understand Duolingo accepting this "word" when typed in an answer by a learner, but not in it giving it as the "preferred" correct answer over the "going to" I had put.
If you're working in the new chunk of courses at the end of the reverse course, I think the sample answers you get when you make an error are run through something like Google Translate, rather than being approved Duolingo answers.
They often use voccabulary other than what Duolingo has taught/is teaching and sometimes don't make sense. When in doubt, look at the answer as given at the top of the sentence discussion.