Speech language pathologists (SLPs) use a variety of tools to diagnose Developmental Language Disorder (DLD) in children. Some tools are well-supported and commonly used, while others are not.
The information below defines current tools and best practices that SLPs should use to assess your child’s language skills. If you don’t understand the SLP’s decisions about the evaluation, observation, or diagnosis, it’s okay to ask for an explanation.
Tools for Diagnosing Developmental Language Disorder (DLD)
Tests for Understanding and Using Language
If your child undergoes an evaluation and DLD is the suspected problem, the SLP will likely administer a number of standardized tests. In general, these are used to compare your child’s ability to other children of the same age. Some tests are more likely to measure common signs of DLD than others.
From age 4 or 5 years and all the way into adulthood, sentence repetition tests are good markers of DLD, as they test short-term verbal memory and knowledge of words and grammar, common weaknesses among people with DLD. Similarly, tests of how well a person can follow verbal directions are useful at all ages. With a younger child the test might include instructions like "Touch the yellow square, then the red square." For an older child or adult, the instructions are more complex, like, "Before touching the red square, touch the yellow square and the blue circle."
For children who are roughly 4 to 9 years old, tests that measure verb use are telling because children with DLD often leave out the verb completely (as in “Jo happy”) or they leave endings off of the verbs (as in “Jo run”).
We know less about the strong signs of DLD in older children and adulthood but difficulty understanding and using figurative language, complex grammar, and narrative or story telling are potential and tests should be selected to measure these skills. If DLD is suspected, the SLP may also test reading and writing, not just talking. That is because challenges with reading and written grammar and spelling are common among older children and adults with DLD. Finally, the SLP may add tests that measure something that seems particularly challenging for your child, even if it is not considered a robust sign of DLD.
The point is not to FIND DLD but to determine the correct diagnosis for YOUR child, whether DLD or something else.
Observation of Daily Activity
More than likely, the reason that you are considering a language evaluation for your child is because you (or a teacher or family member) have noticed that your child is having problems communicating with others or learning in the classroom. Determining the functional impact of any language problem is a key step in determining whether a child has DLD. The SLP will likely measure functional impact by interviewing you (and your child if old enough) and by observing your child communicating with you or others. The SLP will also consider signs that the language problem is limiting academic success. Children with DLD may struggle in the classroom even with the addition of educational assistance programs like Response to Intervention (RTI) or Multi-tiered Systems of Support (MTSS).
Elements that May Impact Developmental Language Disorder Assessment
African American English and Southern White English dialects use verbs differently than Mainstream American English. Tests that rely too heavily on how verbs are used may over- or under-identify DLD. Tests should be selected that look at other grammatical properties that are not verb-related.
Multi-lingual children with DLD will have deficits in both languages. This is not because they are hearing a language other than English. Children should be assessed in both languages. Parents should continue to speak in the language they are most comfortable in and both languages should be supported in therapy. Recommendations to stop using any of the child’s languages are not evidence based.
DLD frequently co-occurs with other problems. This means that some children will have more than one diagnosis. Some frequent co-occurrences are DLD and Attention Deficit Hyperactivity Disorder, DLD and Dyslexia, and DLD and Developmental Coordination Disorder.
Bishop, D. V., Snowling, M. J., Thompson, P. A., & Greenhalgh, T. (2016). CATALISE: A multinational and multidisciplinary Delphi consensus study. Identifying language impairments in children.