nollasääntö
The nollasääntö, often translated as the zero rule or null rule, is a concept primarily discussed in linguistics, particularly in the context of phonology and morphology. It refers to a zero morpheme or an empty element that is phonologically or morphologically significant but does not have a discernible phonetic realization or a tangible form. In essence, it is a morpheme that "is there" in terms of its grammatical function or meaning, but it sounds like nothing.
The nollasääntö is often used to explain grammatical phenomena where a certain form is expected but absent.
The precise implementation and theoretical status of the nollasääntö can vary depending on the linguistic theory