<unk>  (DSM-IV 315.32) is a communication disorder in which both the<unk>  and<unk>  areas of communication may be affected in any degree, from mild to severe.
If someone is being assessed on the Wechsler Adult Intelligence Scale, for instance, this may show up in relatively low scores for Information, Vocabulary and Comprehension (perhaps below the 25th percentile). If the person has difficulty with spatial concepts, such as 'over', 'under', 'here' and 'there', he or she may have arithmetic difficulties,  have difficulty understanding word problems and instructions, or have difficulties using words.
They may also have a more general problem with words or sentences, both understanding and speaking them.
If someone is suspected to have<unk> , then they can go to a speech therapist or pathologist, and receive treatment. Most treatments are short term, and rely on accommodations made in the person's environment, so as to be minimally interfering with work and school functioning.
Mixed receptive-expressive language disorder
Nonverbal learning disorder
Language delay
Pragmatic language impairment
Selective mutism
High-functioning autism
Pervasive developmental disorder
Developmental disability