"There is no food at all."
I was trying to figure this out (poorly, as the lesson doesn't seem to have sunk in), and I offered たべものがまったくないです, which was accepted as correct.
However, having seen the suggested answer above, I'm doubting that it is. Is anyone who knows able to clarify if it is correct or not and, if so, what the difference is between the two sentences?
I believe ない and ありません are generally interchangeable, but ありません is more formal.
I normally wouldn't weigh in unless I knew I was right, but this question has sat here for four months without an answer, and I'd like to know too, so if anyone can confirm or deny, that'd be great! :)
Above, someone mentioned that "mataku" isn't actually a negative adjective ("matai" doesn't exist). So I would think that "mataku nai" in this case wouldn't work. But since "nai" can be used in place of "arimasen" in general for casual speech, it would make sense that it would be correct, or at least give the appropriate idea across even if it's not perfectly correct.
Not an expert opinion, just thinking out loud to see if it makes sense.
The "nai" isn't negating the "mattaku", it's just shorthand for "arimasen", and is acting as the "There is no" part of "There is no food at all." The "mattaku" is the "at all" part, which makes it an adverb, because it modifies the verb (I think.)
From what I know, its position is kinda fluid, presumably because there's only one verb and one noun in the sentence, but it will emphasize whichever word it comes before.
It's like the difference between ちゃわんを三つください (chawan wo mitsu kudasai,) and 三つちゃわんをください (mitsu chawan wo kudasai.) I believe the former is "Please give me three bowls," (answering the question "How many bowls do you want,) while the other is "Please give me three bowls" (answering the question "What do you want?")
I think it's just a matter of emphasis, where putting it before the verb emphasises how completely nonexistent the food is, and putting it before the noun emphasizes how the entirety of the food isn't existing, as far as I can tell. I actually like the way it sounds before the verb better than Duo's suggestion, but I'm not a native so I don't know which would actually be the more common construction.
Sometimes it's not so much about "knowing," it's that some of us want to try typing in Japanese, and the input prediction often insists on kanji. It's actually a nice way to learn kanji on the fly, but it's kind of off-putting when Duolingo is so inconsistent in regards to accepting kanji. Sometimes it works, sometimes it doesn't, and it's not fun to keep second-guessing ourselves.
I'm not sure what you're asking. The first is "There is no food at all" and the second is "There isn't much milk." If you're asking why one uses が and the other uses は, I believe it's related to context.
The first (が) sentence focuses on the food, as if responding to a question specifically about food, rather than just making an observation. The second (は) sentence doesn't have a particular focus, it's just stating that there is not much milk.