In Tolkien’s later writing, Quenya did not have a direct equivalent of English’s comparative “-er” suffix. In linguistic notes from 1966-67, Tolkien said that “A is brighter than B” is expressed using the preposition lá “beyond”: A (ná) calima lá B (PE17/90), where the copula ná- “to be” is optional as usual.
Questions (interrogatives) in Quenya can be indicated by intonation alone, just like in English: túlalye? “you are coming?” However, more often they are marked with the interrogative particle ma. This particle was derived from the ancient root √MA, which was mentioned in several places (PE17/68, 162; VT47/19). Tolkien discussed its use in some detail in Late Notes on Verb Structure (LVS) from 1969:
Just as an interesting aside, a user over on TheTolkien Forum has shared his vision how Tom Bombadil's native language would've looked like. Here is the link: https://www.thetolkienforum.com/threads/bombadillo-an-ancient-language-whose-words-are-mainly-those-of-wonder-and-delight.28916/#post-532604
The subjunctive mood is used for various “unreal” (conditional or hypothetical) statements: things where the speaker is uncertain whether or not they are true. These are slightly different from the optative (things the speaker hopes or wishes were true) and the imperative (actions the speaker demands be done).