Babies can understand the basics of grammar months before they start speaking, scientists say.
Researchers in France have found that infants as young as eight months are able to distinguish between function words – such as articles, pronouns or prepositions – and content words, which include nouns, verbs or adjectives.
The team from the University of Paris say their findings, published in the journal Current Biology, show babies are able to understand grammatical construction much earlier than thought, even though they do not start stringing words together until they are around two years old.
Dr Judit Gervain, a researcher at the Integrative Neuroscience and Cognition Centre at the University of Paris, told the PA news agency: “It is often believed that grammar is something complicated that babies learn once they know a large number of words.
“Here, we show that they already start learning the grammar at the same time as they start learning words.”
The researchers recruited 175 eight-month-old babies from French-speaking households as part of their study.
The infants listened to a four-minute recording of a made-up language in which frequent words, imitating function words, alternated with rarer ones, emulating content words, in six different grammar-learning experiments.
The babies’ word preferences were evaluated by observing how long they looked at circular displays associated with the made-up word.
“We used the head turn preference procedure, which involves a baby sitting on a care-giver’s lap and looking at looming circles in front of them and on each side,” Dr Gervain said.
“We measured how much time an infant spends looking at the circle, which is our indirect measure of how much attention they pay to the sound.”
The researchers found their young test subjects understood that function words were more frequent and came before content words.
Results show the infants were able to quickly adapt to new content words but showed little interest in newly introduced function words.
Writing in their paper, the researchers noted: “Our findings suggest that eight-month-old infants are sensitive to frequency and positional information in the language input.
“Moreover, they use this information to build rudimentary representations of grammar.”