At our recent event at the Federal Reserve Bank of Boston, Commissioner Sherri Killins of the Massachusetts Department of Early Education and Care talked about eggplants.

Eggplants? Yes. The vegetable is a central element in a story Commissioner Killins shared about young children and oral language development, a building block of reading. The tale comes from “It’s Not Complicated! What I Know for Sure About Helping Our Students of Color Become Successful Readers,” by Phyllis Hunter, former director of reading for Houston’s public schools.

Hunter describes three mothers grocery shopping one night with their young children. In the produce section, the first passes a display of glistening, freshly sprayed eggplants. “What’s that?” the child asks. The mother, clearly harried and tired and irritated, tells the child to be quiet. “I don’t know,” the mother says. “Don’t ask me any questions.”

Soon another mother and young child pass the eggplant display. “What’s that?” the child asks. “It’s eggplant,” the second mother replies, “but we don’t eat it.”

Hunter notes, “At least this mother named it. The kid now had a name for the elongated purple vegetable she had never seen before.”

Along comes mother-and-child pair number three. “What’s that?” the child asks.

“It’s an eggplant, one of the few purple vegetables we have. Look at its smooth and shiny skin, its exterior,” the mother replies. “You know, there is a dish called eggplant parmigiana. It is like the chicken parmesan your aunt makes that you like. Let’s buy this eggplant, take it home, slice it open and see how it looks inside. I think it is sort of like a potato with seeds.”

With research showing that kindergarten vocabulary is strongly correlated with high school reading performance, anecdotes like this underscore the importance of engaging young children in conversation that builds their vocabulary and helps them understand the world around them, another key ingredient for learning to read with comprehension. Indeed, the landmark Hart-Risley study that documents evidence of the achievement gap long before children start school focuses on vocabulary. Children in low-income families, it finds, have vocabularies that, on average, are half the size of the vocabularies of their more affluent peers.

As we think about engaging and supporting families to promote children’s development as readers, anecdotes like this show how much difference small, no-cost changes in behavior can make.

Now a question for readers who are parents. Which parent are you? How would you react if you were grocery shopping with a young child after a long day? Chances are I would have been closer to Mother #2 than Mother #3. I probably would have said, “That’s an eggplant.” But I like eggplant, so I hope I would have also offered to buy one and make eggplant parmagiana.