Question: Does Russian have the concept of "sentence fragments" (as English does), and is it also clearly considered a grammatical mistake?
For an optional bonus part of this question, not required though, could you provide a link to a webpage discussing sentence fragments in Russian?
In English grammar, you may have heard about a "sentence fragment".
"Sentence fragments are groups of words that look like sentences, but aren't. To be a sentence, groups of words need to have at least one independent clause. An independent clause is any group of words that contain both a subject and a verb and can stand on its own."
Example: Some girls in the class.
The fragment can be changed to a correct sentence, as follows:
Some girls in the class study together.
Finally, the reason I am asking: When learning Russian, as a beginner, I sometimes encounter what appear to be sentence fragments. Although it could simply be that I am not sufficiently accustomed to the fact that "to be" or "is" are omitted.