In Wikidata, we describe concepts (Q items) and lexemes (L items), where the lexemes may be nouns, verbs, adjectives, etc.
It is usually straightforward to describe the relation from noun lexemes to concepts, e.g., the Danish noun "bil" (https://www.wikidata.org/wiki/Lexeme:L36385) and the English noun "car" (https://www.wikidata.org/wiki/Lexeme:L3648) can both be linked to the car concept (https://www.wikidata.org/wiki/Q1420).
A problem arise when we want to describe non-noun lexemes. For instance, the English verb "drive" does not have an entirely equivalent concept in Wikidata, - in my opinion. It seems closely related to the driving concept (https://www.wikidata.org/wiki/Q999646), but also to a possible driver concept and the noun "drive" (A trip made in a vehicle). Currently, the verb "drive" links to the driving concept with the P5137 (sense/means/denotes, https://www.wikidata.org/wiki/Property:P5137) property, that is usually used to link nouns with concepts. I wonder if that is not a too broad application of the property, as now it seems that the English verb "drive" and the word "driving" (which in Danish is the noun "kørsel") are synonyms..!?
While drive-driving is not that far off conceptually there are other words that have other relations, e.g., the verb "employ" could relate to employer, employee, employment and hiring. In the case of "employer", there is - at least it seems to me - a nomen agentis relationship between employ and employer: an "employer" is a person that "employs". Also there is a (etymological) derivational relationship between employ and employer, employee and employment, - but not hiring.
For adjectives, there are similar problems, e.g., what does "high" relate to? There is a height concept in Wikidata (https://www.wikidata.org/wiki/Q208826) and the adjective "high" relates to this somehow, but so does its antonym "low". One solution to the problem is to define an "adjective concept" for "high" in Wikidata so we can link the word "high" to that concept, but there is a probably a reluctance to do it this way. And even if we would define a "high" concept, so we can link the "high" lexeme with the high concept, there is still the problem of linking the high concept with the height concept or other possible concepts.
WordNet describes relations between word classes with "derivationally related form" which can link, e.g., "employ" with its related nouns, in Python with NLTK:
>>> from nltk.corpus import wordnet as wn
>>> wn.synsets('employ')[2].lemmas()[2].derivationally_related_forms()
[Lemma('employment.n.01.employ'), Lemma('employment.n.03.employment'), Lemma('employee.n.01.employee'), Lemma('employer.n.01.employer')]
but that seems not to describe the detailed semantics between the employ* nouns and the "employ" verb, and I do not see any other way that WordNet describes word-sense-synsets relationships between word classes.
I haven't yet found any scientific articles that builds a broad formalism that could be used for linking non-nouns lexemes in Wikidata with a high degree of specificity. It is unclear to me whether a FrameNet approach will be of help. A property corresponding to WordNet's "derivationally related form" is already present in Wikidata with the P5191 property (https://www.wikidata.org/wiki/Property:P5191).
