Structured input

The linguistic input to language learning is usually thought to consist of simple strings of words.
We think tah input must also include information about words into syntactic phrases. We suggest that the finding that phrase structure cues are a necesary aspect of language input reflects the limited capacities of human language learners, languages may incorporate structural cues in part to circumvent such limitations and ensure successful acquisition.

Another suggestion is tha children are able to learn language because adults speak to them in a special (simplified) language sometimes called motherese or more informal baby talk. This hypothesisalso places a lot of emphasis on the role of the environment in facilitating language acquisition.
Although children prefer to listen to motherese over norlmal adult speech.