"Didn't you order me a plate?"
Translation:ʻAʻole ʻoe i ʻoka i pā mea ʻai naʻu?
Yes, I see that in ordering phrases, articles are dropped. Duolingo, though, has used articles with objects in sentences with ʻoka/order: Ua ʻoka ʻo ia i ka pipi kū. She ordered the beef stew. OR ʻAʻole ʻoe i ʻoka i ka wai? Didn't you order the water? So why wouldnʻt the correct response be ʻAʻole ʻoe i ʻoka i KE pā mea ʻai naʻu (with an article preceding pā mea ʻai)? Is the article optional with ʻoka sentences?
"Pā mea 'ai" is really a meal plate, but I can understand the implication of being a lunch plate. Many may think of a plated meal as a lunch. For example, a Blue Plate Special (an old term) is a lunch plate. I wonder if "pā mea 'ai" is considered an idiom that means plate lunch.
The same sort of thing happens with "ka mea pa'ani" where the phrase literally means plaything but has a common translation of toy. That is my take on it. I hope others can comment on this.
This term originated in Hawai'i English/pidgin as a "plate lunch", but that is a bit of a misnomer since you can eat a plate lunch for any meal. So when it was put into Hawaiian, the meal specific word "lunch" was reassigned as food instead. You are literally saying here "plate (of) food".
That is the thing about languages - words do not always correspond to each other exactly. In Hawai‘i, a plate lunch is a plate of food ordered a cheap eats type of restaurant, but a plate lunch is for any time of day, not just lunch. In Hawaiian, the word lunch was replaced by the more general mea ‘ai meaning food. You just have to remember to use pā mea 'ai as plate lunch and vice versa.
There is the same discussion in Portuguese, that a tablespoon in Portuguese is actually called the equivalent of a soup spoon. You just have to learn the difference and keep it on file mentally.
Unfortunately, the writers for this course have a tendency to offer imperfect English in order to guide the learner into the correct choice of words in Hawaiian. This is not one of those times.