Acquiring complex sentences

Variations in word order are often used for communicative purposes such as to relate events to each other in terms of their timing or causality (e.g. After you've had your dinner, finish your drawing, or We need a coat on because it's raining). In complex adverbial sentences, it is often possible to reverse the order of different parts of the sentence, but the order of events in the real world may remain the same posing a challenge for the language learner (e.g. After you’ve had your dinner, finish your drawingFinish your drawing after you’ve had your dinner). In addition, temporal and causal connectives can convey a range of different meanings, or fulfil different pragmatic functions, adding to their complexity. Understanding how children learn these kinds of complex sentences is important because children’s ability to use complex language flexibly is central to their becoming more sophisticated speakers and to their academic success.

Complex sentences involving adverbial clauses appear in children’s speech at about three years of age yet children have difficulty comprehending these sentences well into the school years. In this project, we examined how children learn to understand and use complex adverbial sentences, and the role of their input and the wider discourse context in supporting understanding through both experimental and corpus work. 

In Study 1, we tested four-year-olds, five-year-olds and adults on four different adverbial clauses (before, after, because, if) to evaluate four different theoretical models (semantic, syntactic, frequency-based and capacity-constrained). Participants completed a forced-choice, picture-selection comprehension test, providing accuracy and response time data. We found that children’s comprehension was strongly influenced by semantic factors – the iconicity of the event-to-language mappings – and that their response times were influenced by the type of relation expressed by the connective (temporal vs. causal).

In Study 2, we looked at the additional impact of contextual information on comprehension of these four adverbials. We tested children and adults on sentences manipulated for clause order and for whether information in the main or subordinate clause was new or already established in the context (given). Our results showed that 4-5 year old children better understand sentences where the given information comes first in the sentence, but only if this information is in a subordinate clause (e.g., Sue paints the fence. Before she paints the fence, she sings a song). In addition, children performed better when sentences were presented with some context in comparison to sentences produced in isolation in Study 1. These results are not readily explained by any current theoretical accounts, and suggest that we need a more developmentally focussed explanation that reflects children's developing language and literacy skills.

In Study 3, we were interested in whether it is possible to enhance children’s ability to comprehend adverbial sentences by increasing exposure to these kinds of complex sentences through a school-based, small group story activity. We recruited a number of schools to the study, and created sets of matched story books in which some children received input of multiple complex sentences, others heard the same stories but with simple sentences used in place of complex sentences. A final control group of children took part in our baseline and post-intervention comprehension measures, but continued with their usual classroom activities in the interim. We’ll summarise the results here as soon as we can.

In Study 4 we analysed dense corpus data from two children between 2 and 5 years of age to establish the relations between the types of adverbial sentences children hear and those they produce. Preliminary results suggest that children’s usage of adverbial sentences generally follows that of their parents in terms of frequency, structure and pragmatics. However, deviations from this pattern are interesting for what they tell us about development. In comparing mothers’ and children’s usage we are able to separate out the effects of frequency, cognitive complexity and pragmatics in explaining the course of acquisition of complex adverbials as well as explaining some of the differences between children’s spontaneous usage and their poor performance in experimental tasks.

To better understand the possible influence of pragmatic variation on children’s acquisition of these adverbials, in Study 5 we coded the because and if Speech-Act sentences of 14 British English-speaking mother-child dyads for the type of illocutionary act they contained, as well as the phrasing of the because- and if-clause. Preliminary results suggest that children’s because Speech-Act sentences were primarily explanations of Statements/Claims, while their if Speech-Act sentences typically related to permission and politeness. Furthermore, while children’s because-sentences showed a great deal of individuality, their if-sentences closely resembled their mothers, containing a high proportion of idiomatic phrases. These patterns provide information about what shapes children’s understanding of each adverbial, and why they have difficulties with comprehension in some instances.

Project Team: Anna Theakston (Lead), Elena Lieven (Lead), Silke BrandtLaura de RuiterHeather Lemen (PhD student).

(Work Package 11)

Selected Outputs

Study 1

  • de Ruiter, L., Theakston, A., Brandt, S., Lieven, E. (2018). Iconicity affects children’s comprehension of complex sentences: the role of semantics, clause order, input and individual differences. Cognition, 171, 202-224.

Study 2

Study 3

We haven’t yet written up this study for publication, but details can be found on the Open Science Framework ( and in the following abstract:

Study 4

Study 5


De Ruiter, Laura and Theakston, Anna and Lieven, Elena and Brandt, Silke (2021). International Centre for Language and Communicative Development: The Effect of Information Structure on the Acquisition of Complex Sentences, 2014-2020. [Data Collection]. Colchester, Essex: UK Data Service. 10.5255/UKDA-SN-853899

De Ruiter, Laura and Theakston, Anna and Lieven, Elena and Brandt, Silke (2021). International Centre for Language and Communicative Development: Iconicity Affects Children's Comprehension of Complex Sentences, 2014-2020. [Data Collection]. Colchester, Essex: UK Data Service. 10.5255/UKDA-SN-853898