Declarative sentence

Declarative sentence is a sentence to which a truth value can be assigned, given a certain situation or circumstance.

Example
(i) is a declarative sentence because we can assign it a truth value (e.g., in the actual world sentence (i) is not true).

(i) The Queen of Holland is bald

Sentences expressing a question or command are not declarative.

Link
Utrecht Lexicon of Linguistics

Other languages

 * German Deklarativsatz