Question: Why not speak about Quenya with its own grammatical terms?

There are still many words I had not found nor here neither on Eldamo:

-Partitive plural -Nominative -Genetive -Dative -Accusative -Ablative -Possessive -Locative -Allative -Instrumental -Respective -Comparison; degrees of comparison: Positive, Comparative, Superlative -Adjetive; PPA, PPP -Participle -Pronoun (personal, possessive and emphatic) -Active, Passive -Indicative -Infinitive -Gerund -Dipthong -Prefix -Interjection -Preposition, postposition -Adverb -Conjunction (as "ar")