kasulikku

Kasulikku is the partitive singular form of the Estonian adjective kasulik, meaning useful or beneficial. In Estonian, adjectives decline to agree with the noun they modify in number and case, and kasulikku appears specifically before a noun in the partitive case. This form is typically used when the noun denotes an indefinite quantity or a non-countable concept, such as information or advice.

Etymology and function: kasulik is formed from the root kasul- (benefit, usefulness) with the suffix -lik, which creates adjectives meaning “having the quality of.” The kasulikku form is the grammatical realization of this adjective when it modifies a noun in the partitive singular. This contrasts with the base nominative form kasulik, which is used in other syntactic positions, such as before a definite noun or in predicate position.

Usage notes: Kasulikku frequently appears with abstract or mass nouns in partitive, signaling an unspecified portion or amount. Common examples include kasulikku teavet (useful information) and kasulikku nõu (useful advice). Because Estonian has no grammatical gender, adjective forms depend on number and case rather than gender.

See also: kasulik (dictionary form of the adjective), Estonian grammar, Partitive case.

In summary, kasulikku is a standard inflected form used to express “useful” in front of a noun that is in the partitive case, reflecting the quantity or scope of the noun rather than a specific count.