In linguistics, a rule that native speakers use to produce new utterances is called productive.

In standard English, the plural -en is no longer productive, for instance. It is used for the plural of ox, oxen, but not for new words ending with -ks. In the hacker sociolect, however, the plural -en is productive, as is illustrated by the plurals boxen, unixen and emacsen, for example. In a similar manner, English strong verbs, which use ablaut to indicated tense, are no longer productive. All new English verbs are weak verbs.

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Productive also means positive or beneficial, and formative and constitutive.