Carol Chomsky, a linguist and education specialist whose work helped illuminate the ways in which language comes to children, died on Friday at her home in Lexington, Mass. She was 78.

The cause was cancer, her sister-in-law Judith Brown Chomsky said.

A nationally recognized authority on the acquisition of spoken and written language, Professor Chomsky was on the faculty of the Harvard Graduate School of Education from 1972 until her retirement in 1997. In retirement, she was a frequent traveling companion of her husband, the linguist and political activist Noam Chomsky, as he delivered his public lectures.

Carol Chomsky was perhaps best known for her book, “The Acquisition of Syntax in Children From 5 to 10” (M.I.T. Press), which was considered a landmark study in the field when it appeared in 1969. In it, she investigated children’s tacit, developing awareness of the grammatical structure of their native language, and their ability to use that awareness to extract meaning from increasingly complex sentences over time.

Young children, Professor Chomsky found, could distinguish no difference in meaning between superficially similar sentences like “John promised Bill to shovel the driveway” and “John told Bill to shovel the driveway”  they could not discern who did the shoveling in each case. Older children, she found, could do so automatically, without having been formally taught.