In optimality theory, the essence of both language learning in general learnability and language acquisition actual development children go through entails the rankings of constraints from an initial state of the grammar to the language specific ranking of the target grammar McCarthy, .
O'Sullivan, E. This theory shares many of the same explanations as the other three theories. Wie Kinder sprechen lernen. The teacher as language learner: worlds of difference?
Multilingual Matters, Essentially it is impossible for a young child to voice concepts that are unknown to them; therefore, once a child learns about their environment, then they can map language onto their prior experience.
MT constructions act as a default, stepping in when our memory fails, offers nothing else and lets us down.
Linguistic forms with high token frequency will be learned early and lead to more strongly entrenched linguistic representations and seem to protect the child from error.