The Interrogatives in Sargaĺk

In Sargaĺk, there are four interrogative pronouns -

t'əre: who
səre: what (for count-noun-like things)
bəre: what (for mass-noun-like things)
zəre: what (for utterances and thoughts)

These sometimes appear in a variety of verbs, adjectives and nouns.
The interrogative pronouns are inflected for case (and number), but t'əre is most often masculine except if a) the expected answer is feminine, or b) the answer is required by the speaker to be feminine. The three others are always inflected in the masculine except if they are adjectives; as adjectives, they are generally suffixed to the noun.

Adjectives 

Adjectives are generally formed from other stems by adding suffixes. These suffixes further are inflected for case. 

brəsep - full (of liquid or indifferentiable mass)
zrəsep - full of things to say
t'rəsep - full of people

The suffix -sep means 'full of' or 'saturated with'. The -e- turns to -ə- when case suffixes are added.

sərkuy - 'whatless', insignificant
bərkuy - 'empty'
zərkuy - 'silent' but also 'unthinking' depending on context
t'ərkuy - 'one of a kind' (of a person)

The meaning of -kuy generally is '-less'.  -y- disappears before consonant-initial case suffixes.

From these, nominalizations can be formed, but the usual Sargaĺk discourse structure seldom calls for abstract nouns like '-lessness' or '-fulness'. -kir, however, is the usual abstract nominalization for adjectives: brəsefkir: fullness, t'ərkukir: quirkiness, zərkukir: silence, stupidity.

These can be used with appropriate case inflections to signify 'a X one', including the uninflected form for the absolutive case. 'Brəsep' thus can also signify a full container, 'zrəsep' a person with an issue to speak of, or a story-teller, or somesuch, and a t'rəsep can be a full house or a legion or anything like that.

Nouns

There are only a few derivations from these that give nouns without an intermediate adjective or verb in the derivation chain. Three primary examples, however, are

srənki (f) - a question (as to what (səre or bəre))
t'rənki (f) - a question (as to whom)
zrənki (f) - a question (as to what the listener is thinking)

Verbs

Verbs for asking are obvious contenders for this, and include

zrənoj, t'rənoj, brənoj, srənoj

Brənoj and srənoj both are used when the question pertains to time, place, etc, depending on the size and type of the expected answer: spans of time or large locations or maritime locations often are asked for with brənoj, specific days or times of day or weeks or months are asked for with srənoj.

There is also a verb k'yenoj which signifies asking a binary question. K'ye also is the particle that indicates tag questions, and can be initial or final in the tag question.

Other verbs for asking specific types of questions also exist, such as

bnaroj - ask for permission

The idea that asking for whom is somehow the primary type of question can be found in the following verbs, which can refer to any kind of question:

t'rəgrošaj: to overwhelm with questions
t'rəkoŋpoj: to ask questions with the intention of misleading the listener
t'rəroroj: to ask stupid questions
t'rəksturij: to ask a question without an intention to listen to the answer
t'rəksomaj: to ask the same question repeatedly
t'rəparuj: to ask a question in order to embarass someone