When one reports a problem with an exercise, DL offers the reason that "The sentence is not gramatic". I've searched for "gramatic" with these results:
There is a music group "Gramatik". "Gramatic" may be a word in some other languages than English. "Gramatical" appears to be a word in some other languages such as Galician. The New Oxford American Dictionary (2nd ed.) lists "-grammatic" as a combinatorial form of nouns ending in "gram", such as "cryptogrammatic". The Concise OED (revised 10th ed.) lists only "grammatical" as the English adjective.
May I suggest DL change its example to "e.g., The sentence is not grammatical" or, if line length is an issue, "e.g. This is not grammatical."
I think you should move this to troubleshooting. Basically you mean that the feedback needs to be "Grammatical".
P.S. a Screenshot would probably help them track down this problem.
This is what I see with on the "Report a Problem" dialogue:
I deliberately answered a review question wrong be able to check this. Are we talking about the same thing?
The problem appears on my smartphone (Android Samsung Galaxy Note 3). Displayed in landscape mode, it reads, "e.g. The sentence is not gramatically corre", being cut off at that point. I believe that "grammatically" is misspelled. I'm ignorant as to how to take a screen shot of it, or how to post one here.
Ah. This is what displays on my Nexus 10 tablet in both landscape and portrait orientation:
Yes, it should be spelled "grammatically" rather than "gramatically." My Nexus 5 phone displays the example text similarly to what you're describing. The example in the text box is truncated on initial display due to the smaller screen's limitations, but once it gains focus, the entire message can be seen in edit mode. I'd say the only issue here is a spelling error, that hopefully will be corrected if brought to the dev's attention.