Language Development and Disorders (LDD): research projects

Research studies

Understanding language comprehension in bilingual children


One of the major concerns often voiced by caregivers of bilingual children is that, as a result of exposure to two languages, children might experience a certain degree of linguistic confusion leading to delayed or even incomplete acquisition of one or both of their languages. There is in fact strong research evidence that young children have a capacity for language learning that makes them more than able of dealing with two languages at once. At the same time, it would be misleading to treat a bilingual child as the sum of two monolinguals. A serious developmental perspective on bilingualism must take into account the possibility of varying degrees of separation between an individual’s two languages. A growing body of research shows that children who are simultaneously exposed to two languages from birth on a regular basis are very similar to monolingual children in their knowledge of language. By and large, simultaneous bilingual children produce grammatically appropriate expressions in each of their two languages. At the same time, there is also an increasing consensus in the research community that bilinguals differ in subtle ways from monolinguals. More specifically, bilingual children appear to be somewhat delayed compared to monolinguals of the same age when understanding a sentence requires them to take into account different types of linguistic and contextual information.

One key area where the integration of multiple sources of information is crucial is the comprehension and use of personal pronouns (e.g. 'he' and 'she'). By their very nature pronouns have no fixed reference. To understand what 'he' or 'she' mean we have to find out whom they refer to; i.e. we have to find their antecedent. This is a non-trivial task in the context of spoken language where decisions have to be made in a matter of milliseconds to understand what is being said. Upon hearing a pronoun like ‘she’, the listener has to process a number of different linguistic cues such as the syntactic function of the possible antecedent (subject vs. object); the gender of the pronoun (masculine or feminine morphology); the meaning of previous sentences (semantics).
Research shows that even monolinguals find the interpretation of pronouns rather demanding into their school years, and that bilingual children find this complex process even more taxing, especially if they speak two languages like English and Spanish/Italian that are quite different with respect to the distribution of pronouns. These preliminary findings are interesting, but there is considerable scope for investigating the nature of the differences between bilinguals and monolinguals in more depth, both in terms of the nature of the comprehension process itself, and in terms of the role played by bilingualism and the specific language combination that children speak.

Duration of the project


Funding body

The Leverhulme Trust

Members of the project

Dr Ludovica SerratricePrincipal investigator
Prof. Antonella SoraceCo-investigator
Dr Michela BaldoResearch associate


The overall aim of this project is to test whether the observed differences between bilingual and
monolingual children are actually the result of processing difficulties as measured by the on-line tracking of eye movements during pronominal resolution tasks where children have to integrate information coming from syntax, morphology, pragmatics and verb semantics. More specifically, six eye-tracking experiments (three in Italian and three in Spanish) with English-Italian and Spanish-Italian bilingual children, and Italian and Spanish monolingual peers will address the following three objectives:

1) Objective 1: to test whether any differences between bilingual and monolingual children’s
comprehension of pronouns are to be ascribed to bilingualism itself, the specific cross-linguistic
difference between English and Italian, or a combination of these two factors.

2) Objective 2: to investigate to what extent the comprehension of pronouns in real time in children who learn closely typologically related languages like Spanish and Italian is equally affected in the two

3) Objective 3: to find out whether differences between bilingual and monolingual children in pronoun
comprehension decrease over time.


In a series of six experiments we will record children's eye movements as they look at colour pictures presented on a computer screen and listen to digitally recorded sentences describing an event (e.g. Spanish: 'La madre dice hola a la niña mientras ella bebe leche'/English 'The mother says hi to the girl while she drinks some milk').

By monitoring children's eye movements in real time we will know which referent they first look at when they hear a pronoun. For instance when they hear 'ella' as in the previous Spanish example, will they look first at the mother or at the girl?

The experiments will focus on different types of linguistic cues (syntax, morphology and semantics) that should help children in understanding whom a pronoun refers to. This will provide us with extremely detailed data on how both bilinguals and monolinguals make use of different sources of linguistic information during the comprehension process.

We also intend to explore whether the differences between bilinguals and monolinguals depend more on the language pair that children are acquiring, or on the fact that they are learning two languages rather than one, regardless of what they are. To address this issue we will compare children learning two languages like Spanish and Italian (very similar in the distribution of pronouns) with children learning languages like English and Italian (quite different in the distribution of pronouns). The comparison of the bilinguals with monolingual Spanish and Italian children will reveal the extent to which differences exist between monolinguals and bilinguals.

Finally, to test whether any differences between bilinguals and monolinguals decrease over time we will include a younger group of children (6-7 years of age) and an older group of children (8-10 years of age).