Substantiivilausetta

Substantiivilausetta, or nominal clause, is a type of subordinate clause in Finnish grammar that functions as a noun within a larger sentence. It represents a statement, a question, or another content unit and can serve as the subject, the object, or a predicative complement of the main clause.

Finnish nominal clauses are typically finite and are introduced by specific subordinating elements. The most common is the that-clause, built with the conjunction että (that). Indirect questions are another major subtype, formed with question words such as missä, mitä, kuka, miksi, or how forms, and they embed a question within the main clause without directly asking it. Examples include Uskon että sade loppuu pian (I believe that the rain will end soon) and En tiedä missä hän asuu (I don’t know where he lives). In addition, nominal clauses can appear with appositive or complementive structures, as in Se, että hän tuli (The fact that he came).

Syntactically, substantiivilausetta behave like a noun phrase within the sentence: its content is treated as a single propositional unit, and the verb inside the clause agrees with its own subject rather than with the main clause’s subject. They are distinct from adverbial clauses, which modify the verb or the sentence as a whole rather than acting as a noun.

Punctuation and stylistic use vary, but subordinate nominal clauses are a common mechanism for reporting thoughts, statements, questions, or propositions without repeating them as separate sentences.