Need to flag singular countable nouns used without a determiner.

> A month ago, especially smaller **model** would fall into a rabbit hole it dug for itself and would never recover.

should be

> A month ago, especially smaller **models** would fall into a rabbit hole it dug for itself and would never recover.

or

> A month ago, **especially a smaller model** would fall into a rabbit hole it dug for itself and would never recover.

(Adding "the", "this", "that", "my", etc. would also make it grammatical.)

This is a common mistake made by native speakers of Slavic languages and many Asian languages.

Use the two quoted sentences as acceptance examples, along with the listed alternatives using a plural noun or determiner. Find the grammar-checking rule entry point and its existing tests, then verify that singular countable nouns without determiners are flagged while the grammatical alternatives are accepted.

Written by the indexing model from the issue text.