Evidence of accelerated learning

Gleitman says the biggest clue to the accelerated learning is the fact that it occurs when the child starts making sentences. "When the child begins talking at two words at a time, this is the first evidence that they understand something about grammar and language," she says.

https://whyfiles.org/058language/baby_talk2.html

I realised this early in my own teaching practice that as students began to add simple basic communicative language structures together and did this on a regular basis that not only did they start building their vocabulary but they were also able to express and communicate their requests in simple accurate forms of conventional language modes of whakarongo (listening) , kōrero (speaking) and tuhituhi (writing).