In linguistics, free variation is the phenomenon of two (or more) sounds or forms appearing in the same environment without a change in meaning and without being considered incorrect by native speakers.[1][2]
Sociolinguists argue that describing such variation as "free" is very often a misnomer, since variation between linguistic forms is usually constrained probabilistically by a range of systematic social and linguistic factors, not unconstrained as the term "free variation" suggests.[3] The term remains in use, however, in studies focused primarily on language as systems (e.g. phonology, morphology, syntax).[4]