は is used to stress the negativeness. に itself is needed to specify the place of existance and this cannot be replaced, so は follows に and becomes the compound particle には.

strange, in both positive examples it accepted my answer, which both times lacked the 'ha'.

Yeah how come they don't use 'は' in the positive version?

I checked the comments to find out why as well...

I don't put that "ha" in my sentence and it is accepted tho

Not sure if I qualify as having much experience, but this question came up in my Japanese class and my teacher worked it out as いいえ、とうきょうはにすんでません Note the placement of [は] and [に] respectively - the two particles can be interchanged without a direct deviation of the meaning (both usages indicate that you do not live in Tokyo). The indirect meaning, however, does deviate you said correctly that the [は] positioned after the [に] does give an indication that you live somewhere BUT Tokyo, whereas the particle order in my teachers' sentence above merely states that you don‘t live in Tokyo. This is comparable to the two particles [で] and [は] and their negative connotations: here's a website URL that can explain the [で] and [は] transformation way better than I can (also applicable to the [は] and [に] in part): http://selftaughtjapanese.com/2015/02/26/japanese-particle-combination-%E3%81%A7%E3%81%AF-de-wa-and-%E3%81%98%E3%82%83-ja/

But overall, I would say that the [は] at the end is merely used in common speech to put emphsis on the fact that you do indeed live somewhere, just not Tokyo.

Definitely interested in this too. And thanks for the explanation and source too.

Certain particles can be used to specify things such as location and so forth the thing is it wasnt introduce earlier to explain. But the sentence is grammatically correct when used with only に.

That's exactly the feeling I get from this example sentence as well.

いいえ、東京に住んでいません (iie, toukyou ni sunde imasen) was accepted for me.

It's the oral form. 住んでない/住んでません

There are two types of ています. One represents a progressive action, and another represents a state.

In this case 住んでいます is a state representing living (in a place). It does not representing an progressive/continuous action.

(I think both "live in Tokyo" and "am living in Tokyo" mean the same thing, but definitely more natural using "live in Tokyo.")

で when talking about the location where an action takes place, に when describing the location of the subject after a stateful verb finishes transitioning into a state.

may be there is an option: すんでいない which is the simple form of すんでいません

It is not wrong. It is a natural sentence. You dropped the stress to the negative clause that comes after. That's all.

I used only ni and my answer was marked as a mistake...

Yes it is possible.

It cannot be ありません. It must be いません (います used to represent continuous state of a verb - すんでいます)

The verb すみます (sumimasu, live) is written as 住みます in kanji. The contributors have been adding more kanji to the course, and some of the new kanji don't have a voice for them yet, or sometimes the voice is using the wrong reading of the kanji and is disabled. If you open the discussion thread, it's written only in hiragana and the voice reads the entire sentence.

yes, your understanding is correct. Whether or not to use は depends on the need of stressing the negative.

Without knowing your answer, it's hard to say anything, but I would assume that there was a word or syllable missing from your answer that duolingo incorrectly indicated to you was a missing comma. This sometimes happens to me, and when I check the answer they gave me with the expected answer I realize I made a different mistake than what they told me was the mistake. That said, it could just be a glitch as well.

とうきょうには すんでいない is also correct, so there is no need to include せん in the answer.

That's frustrating. If you report the hints (there's a specific option for that for the PC version, or I know on iPhone there's a more general report any issue button), it does get addressed eventually (but eventually could be months later).

You mean you used に instead of には and marked incorrect? In which case it should not be incorrect and you can report it.

I think copying and pasting your specific answer and explaining what kind of question it was ("type what you hear", "write this in Japanese") would get you better feedback. I don't know what your answer was, but I made a comment above saying that いいえ、東京に住んでいません was accepted for me without the は. Did you write it differently? Maybe no one has submitted an error report for the exact combination of kana and kanji that you wrote, or maybe you made another mistake in your answer? If there's something actually broken in this question you can always submit an error report or a bug report.

About には, you can plug in 東京には住んでいません into google and get over 20,000 hits, so it's certainly used in Japanese.

You can submit a bug report or post in the troubleshooting forum.

Glad to hear it's not just a me problem. I click "skip" and it marks it as wrong, giving me the correct answer. I copy that and paste it when it comes back around.

I’m surprised that’s in the database because it’s not proper grammar , but it is acceptable in spoken Japanese to drop the い when using the -te imasu form.