- Definition : a theory originally from research into first language acquisition, proposed by Brown (1973) and suggesting that children would acquire the morphemes of their first language in a set order.
- Example : Children acquiring English as their L1 will always acquire the -ing morpheme earlier than the third person -s morpheme.
- Extensions of the theory : Dulay and Burt (1974) suggested that the hypothesis might also be valid for children learning a second language. Krashen then picked up on the hypothesis in the 80s, incorporating it into his Monitor Model giving it its current name, popularising it and extending it to adult learners – for whom the evidence is much more shaky. For a critique of this theory, see : Johnson, H. The Natural Order Hypothesis : Definition and Criticism
- Reference : Dulay, H. S., and Burt, M. K. (1974). Natural sequences in child second language acquisition. Language Learning, 24, 37-53
Ellis, R. Second Language Acquisition, OUP
