Q. interrogative pronouns grammar.
Interrogatives in Quenya were derived from the root √MA (PE17/68, 161-162; PM/357). This root also seems to be the basis for the neuter indefinite pronoun ma “something” (PE22/154). There are various interrogative forms derived from this root, many of which are simply the root with various Quenya noun case suffixes added:
The origins of most of these are obvious. The etymology of man “who” is unclear, but this word was established very early in Tolkien’s writing, appearing in the first drafts of the ᴱQ. Oilima Markirya poem from the late 1920s. It therefore may have been a holdover from earlier conceptions. Alternately, it could be an animate variant of inanimate √MA, as with examples like √ARA “noble” vs. √ARA-N “noble one” = “king” (hat tip to Röandil for this suggestion). The interrogative mana “what” may be an adjectival form repurposed for substantival use as seen with sana “that”.
Unlike English, there is no sign that Quenya interrogatives are used as relative pronouns; Quenya has a distinct set of pronouns for that purpose. For more information about interrogative phrases, see the entry on interrogative verb formations.
Conceptual Development: In the Gnomish Lexicon of the 1910s Tolkien gave a distinct interrogative root ᴱ√DO, though he did not give it any Qenya derivatives (GL/30). In this document, ᴱ√MA was given as the root of indefinites (GL/55), and in the Early Qenya Grammar (EQG) of the early 1920s, ᴱQ. -(u)ma was given as a suffix that functioned like an indefinite article (PE14/42, 71). Also in EQG there was a particle of uncertainty ᴱQ. mai “if” (PE14/59). In one place this was used to form a question: mai ke·tule “do you come?” (PE14/53), but that does not seem to be its only or even its primary function at this conceptual stage.
However, by the late 1920s Tolkien was consistently using ᴱQ. ma² and its derivatives as an interrogative particle (PE16/77), starting with the Oilima Markirya drafts mentioned above. It seems to have retained this as its main function thereafter, aside from some minor variations like the aforementioned neuter indefinite pronoun ma.
Neo-Quenya: Neo-Quenya writers typically follow the above patterns to coin new interrogatives, some of which eventually show up in new publications of Tolkien’s own writing. For example, masse “where” was originally coined as a neologism but later appeared as an attested word in PE22. Neologism examples include:
Element In