first criterion. tomblin et al. proposed the episli criterion, based on five composite scores representing performance in three domains of language (vocabulary, grammar, and narration) and two modalities (comprehension and production). children scoring in the lowest 10% on two or more composite scores are identified as having language disorder. the second criterion, persistence of language problems, can be difficult to judge in a young child, but longitudinal studies have shown that difficulties are less likely to resolve for children who have poor language comprehension, rather than difficulties confined to expressive language. in addition, children with isolated difficulties in just one of the areas noted under 'subtypes' tend to make better progress than those whose language is impaired in several areas. the third criterion specifies that dld is used for children whose language disorder is not part of another biomedical condition, such as a genetic syndrome, a sensorineural hearing loss, neurological disease, autism spectrum disorder or intellectual disability – these were termed 'differentiating conditions' by the catalise panel. language disorders occurring with these conditions need to be assessed and children offered appropriate intervention, but a terminological distinction is made so that these cases would be diagnosed as language disorder associated with the main diagnosis being specified: e.g. "language disorder associated with autism spectrum disorder." the reasoning behind these diagnostic distinctions is discussed further by bishop (2017). benchmarks for children with developmental language disorder common red flags at one year of age: no reaction to sound no babbling difficulty feeding no imitation limited use of gestures at two years of age: makes minimal attempts to communicate with gestures or words has not spoken their first words difficulty following simple directions inconsistent response to "no" at three years of age: limited use of speech incomprehensible speech limited understanding of simple questions difficulty naming objects frustration related to communication at four years of age: uses only 3-word phrases speech is not understandable to parents takes a long time to understand others difficulty asking questions and finding words to express thoughts at five years of age: speaks only in simple sentences speech is not understandable to teachers difficulty answering questions difficulty with complex directions difficulty telling stories difficulty with peer interactions assessment assessment will usually include an interview with the child's caregiver, observation of the child in an unstructured setting, a hearing test, and standardized tests of language. there is a wide range of language assessments in english. some are restricted for use by experts in speech-language pathology: speech and language therapists (salts/slts) in the uk, speech-language pathologists (slps) in the us and australia. a commonly used test battery for diagnosis of dld is the clinical evaluation of language fundamentals (celf). assessments that can be completed by a parent or teacher can be useful to identify children who may require more in-depth evaluation. the children’s communication checklist (ccc–2) is a parent questionnaire suitable for assessing everyday use of language in children aged four years and above who can speak in sentences. informal assessments, such as language samples, are often used by speech-language therapists/pathologists to complement formal testing and give an indication of the child's language in a more naturalistic context. a language sample may be of a conversation or narrative retell. in a narrative language sample, an adult may tell the child a story using a wordless picture book (e.g. frog where are you?, mayer, 1969), then ask the child to use the pictures and tell the story back. language samples can be transcribed using computer software such as the systematic analysis of language software, and then analyzed for a range of features: e.g., the grammatical complexity of the child's utterances, whether the child introduces characters to their story or jumps right in, whether the events follow a logical order, and whether the narrative includes a main idea or theme and supporting details. treatment treatment is usually carried out by speech and language therapists/pathologists, who use a wide range of techniques to stimulate language learning. in the past, there was a vogue for drilling children in grammatical exercises, using imitation and elicitation, but such methods fell into disuse when it became apparent that there was little generalisation to everyday situations. contemporary approaches to enhancing development of language structure, for younger children at least, are more likely to adopt 'milieu' methods, in which the intervention is interwoven into natural episodes of communication, and the therapist builds on the child's utterances, rather than dictating what will be talked about. interventions for older children, may be more explicit, telling the children what areas are being targeted and giving explanations regarding the rules and structures they are learning, often with visual supports. in addition, there has been a move away from a focus solely on grammar and phonology toward interventions that develop children's social use of language, often working in small groups that may include typically developing as well as language-impaired peers. another way in contemporary remediation differ from the past is that parents are more likely to be directly involved, but this approach is largely used with preschool children, rather than those whose problems persist into school age. for school-aged children, teachers are increasingly involved in intervention, either in collaboration with speech and language therapists/pathologists, or as the main agents of delivery of the intervention. evidence for the benefits of a collaborative approach is emerging, but the benefits of asking education staff to be the main deliverers of slt intervention (the "consultative" approach) are unclear. when slt intervention is delivered indirectly by trained slt assistants, however, there are indications that this can be effective. in this field, randomized controlled trial methodology has not been widely used, and this makes it difficult to assess clinical efficacy with confidence. children's language will tend to improve over time, and without controlled studies, it can be hard to know how much of observed change is down to a specific treatment. there is, however, increasing evidence that direct 1:1 intervention with an slt/p can be effective for improving vocabulary and expressive language. there have been few studies of interventions that target receptive language, though some positive outcomes have been reported. how to help a child with developmental language disorder talk to the child often to help them learn new words read to them every day. point out words you see point to signs in the grocery store, at school, and outside speak to the child in the language you know best listen and answer when the child talks get the child to ask you questions give the child time to answer questions keep them in school: children who are school-refusers have poorer language skills overall, and a higher incidence of language impairments outcome longitudinal studies indicate that problems are largely resolved by five years of age in around 40% of four-year-olds with early language delays who have no other presenting risk factors. however, for children who still have significant language difficulties at school entry, reading problems are common, even for children who receive specialist help, and educational attainments are typically poor. poor outcomes are most common in cases where comprehension as well as expressive language is affected. there is also evidence that scores on tests of nonverbal ability of children with dld decrease over the course of development. dld is associated with an elevated risk of social, emotional and mental health concerns. for instance, in a uk survey, 64% of a sample of 11-year-olds with dld scored above a clinical threshold on a questionnaire for psychiatric difficulties, and 36% were regularly bullied, compared with 12% of comparison children. in the longer-term, studies of adult outcomes of children with dld have found elevated rates of unemployment, social isolation and psychiatric disorder among those with early comprehension difficulties. however, better outcomes are found for children who have milder difficulties and do not require special educational provision. prevalence epidemiological studies of children in the us and the uk converge in estimating the prevalence of dld in five-year-olds at around 7%. recently, an australian population based study demonstrated comparable prevalence of dld amongst 10 year-old children. therefore, the prevalence is about one in every 15 children. by these statistics, in a classroom of 30 students, 2 would have dld. in research by tomblin et al., prevalence of dld in racial/ethnic groups was highest in native americans, with african americans being the next highest, followed by hispanic people, and then white people. no students of asian descent presented with dld; however, other research does indicate that dld is present in children of asian descent. research much research has focused on trying to identify what makes language learning difficult for some children. a major divide is between theories that attribute the difficulties to a low-level problem with auditory temporal processing, and those that propose there is a deficit in a specialised language-learning system. other accounts emphasise deficits in specific aspects of learning and memory. it can be difficult to choose between theories because they do not always make distinctive predictions, and there is considerable heterogeneity among children with dld. it has also been suggested that dld may only arise when more than one underlying deficit is present. developmental language disorder in adults relatively little research has been conducted to test the outcomes of dld in adults. in a study comparing 17 men with dld to siblings without dld, researchers found that the dld men had normal intelligence with higher performance iq than verbal iq. the participants still exhibited a severe and persisting language disorder, severe literacy impairments, and significant deficits in theory of mind and phonological processing. within the dld cohort, higher childhood intelligence and language were associated with superior cognitive and language ability at final adult outcome. in their mid-thirties, the dld cohort had significantly worse social adaptation (with prolonged unemployment and a paucity of close friendships and love relationships) compared with both their siblings and national child development study (ncds) control cohorts, matched on childhood iq and social class. self-reports showed a higher rate of schizotypal features but not schizoaffective disorder. four dld adults had serious mental health problems (two had developed schizophrenia).