The Sentence Structure sub-test (SST) of the Clinical Evaluation of Language Fundamentals aims to ``measure the acquisition of grammatical (structural) rules at the sentence level''. Although not originally intended for use with bilingual children, CELF raw scores are often used to estimate the English proficiency of bilingual children.One of the most robust predictors of language proficiency in bilinguals is the amount of exposure they have experienced in the language in question. Surprisingly, however, exposure to English did not predict SST scores in a group of 5- to 7-year-old bilinguals, in sharp contrast with other proficiency tests used with the same children. This study queries the reliability of the SST as an index of children's ability to deal with structural complexity in sentence comprehension, and demonstrates that cognitive complexity acts as a major confound in the task, affecting monolinguals (n = 87) and bilinguals (n = 87) alike.

The Sentence Structure sub-test (SST) of the Clinical Evaluation of Language Fundamentals (CELF) aims to “measure the acquisition of grammatical (structural) rules at the sentence level”. Although originally designed for clinical practice with monolingual children, components of the CELF, such as the SST, are often used to inform psycholinguistic research. Raw scores are also commonly used to estimate the English proficiency of bilingual children. This study queries the reliability of the SST as an index of children's ability to deal with structural complexity in sentence comprehension, and demonstrates that cognitive complexity induces a considerable confound in the task, affecting 5- to 7-year-old monolinguals (n = 87) and bilinguals (n = 87) alike.