Regardless of the language they are learning to speak, young children learn vocabulary in fundamentally the same way, according to a study by researchers at the National Institute of Child Health and Human Development of the National Institutes of Health.
The researchers found that, for the seven languages studied, nouns comprise the greatest proportion of 20-month-old children's vocabularies, followed by verbs and then adjectives.
The findings appear in the July-August issue of Child Development.
"This study shows that while languages may differ greatly, the sequence by which young children learn the parts of speech appears to be the same across different languages," said Duane Alexander, M.D., Director of the NICHD. "By learning about the normal progression of language development, we may be able obtain information that will help children who are having difficulty learning language."
For the study, Marc Bornstein and Linda Cote, researchers in NICHD's Child and Family Research Laboratory collaborated with researchers in Argentina, Belgium, France, Israel, Italy and the Republic of Korea to study language development in children learning to speak Spanish, Dutch, French, Hebrew, Italian, Korean, and American English.
In all, 269 mothers of children age 20 months took part in the study. Of the children in the study, 117 were girls, and 152 boys. All of the children were firstborn, had been born at term and spoke only one language (the main language of the community they lived in.) The mothers filled out a standardized questionnaire designed to gauge the extent of their children's vocabularies. The questionnaire included examples of nouns, verbs, adjectives, and "closed-class" words—pronouns, question words, prepositions and articles, and quantifiers.
"Specifically, mothers in every country reported that their children said significantly more nouns than any other word class (verbs, adjectives, closed-class words)," the researchers wrote.
The researchers added that the finding held true regardless of whether the language spoken tends to emphasize nouns, as does American English, or verbs, as does Korean.
"There is a universal order to how children learn language," Dr. Bornstein explained. "No matter what language they speak, children are acquiring classes of words in a particular order because of what the children are bringing to the task."
Dr. Bornstein theorized that children learn nouns first because nouns are concrete things that can be seen and touched. Verbs and adjectives are more abstract, and so are more difficult concepts for children's minds to grasp.
The NICHD is part of the National Institutes of Health (NIH), the biomedical research arm of the federal government. NIH is an agency of the U.S. Department of Health and Human Services. The NICHD sponsors research on development, before and after birth; maternal, child, and family health; reproductive biology and population issues; and medical rehabilitation. NICHD publications, as well as information about the Institute, are available from the NICHD Web site, http://www.nichd.nih.gov, or from the NICHD Information Resource Center, 1-800-370-2943; e-mail NICHDInformationResourceCenter@mail.nih.gov.