NurtureShock: New Thinking About Children by Po Bronson and Ashley Merryman includes a wide collection of thought-provoking research on children and learning. The last chapter focuses on language, with some of its lessons applicable to both early language acquisition by babies and later language learning as well.

Babies learn to decipher speech partly by lip-reading: they watch how people move their lips and mouths to produce sounds. One of the first things that babies must learn—before they can comprehend any word meanings—is when one word ends and another begins. Without segmentation, an adult’s words probably sound about the same to an infant as does his own babbling. At 7.5 months, babies can segment the speech of people they see speaking. However, if the babies hear speech while looking at an abstract shape, instead of a face, they can’t segment the sounds: the speech once again is just endless gibberish. (Even for adults, seeing someone’s lips as he speaks is the equivalent of a 20-decibel increase in volume.)

When a child sees someone speak and hears his voice, there are two sensory draws—two simultaneous events both telling the child to pay attention to this single object of interest—this moment of human interaction. The result is that the infant is more focused, remembers the event, and learns more.
–pp. 203-204).

In addition to reporting that multisensory input helps, the authors include research from University of Iowa (p. 217-218) that hearing language from multiple speakers accelerates learning.

This supports our anecdotal evidence that hearing slight variations in accent help people in learning new phrases. When we acquire a new language, we are not only acquiring vocabulary, but learning to differentiate phonemes and process new sounds.

Grammar teaches Vocabulary

Bronson and Merryman also discuss the value of variation sets where children learn vocabulary where words are repeated in varying contexts. Initially a noun is easily recognized when it follows a “word frame” such as “Look at the ___.” Then using some repetition to highlight variation helps with learning. They point out that “grammar teaches vocabulary.”

For instance, a variation set would thus be: “Rachel, bring the book to Daddy. Bring him the book. Give it to Daddy. Thank you, Rachel—you gave Daddy the book.”
— p. 219

This is exactly how I like to learn a new language, learning vocabulary and grammar together in context. I am often frustrated that such variation sets are hard to assemble in typical language workbooks. I think this could inform how we create “phrase lists” in Mightyverse and I can’t wait until we make the tools a little easier so we can let other folks experiment with lists of their own making.