"I eat lunch."
Make it polite. I got it marked wrong for excluding it, which seems harsh.
I see you are achieving a lot here. When you finish the entire course for a language here, where do you go next on the internet to solidify further? I feel like I would first have to do a bunch of exercises memorizing vocabulary from all the kanji and advanced characters much the way elementary students in Japan would have to do for this first language I am tackling. What is the next general step in language learning for all languages given one has completed a Duolingo course?
I am using Human Japanese app in conjunction with Duolingo. It teaches a lot of the same lessons, but in a much more in depth way.
In addition, I recommend the Hello Talk app. You can speak with native Japanese speakers who are looking to learn English, giving you some real practice in using the language.