A: Across time and cultures, children typically develop their oral language without much effort. Oral language is an important mean of communication, and it is essential for social development, and for some other fundamental aspects such as learning, reading comprehension, academic and social integration.
Oral language is a complex system where everything is interconnected. It involves both receptive (comprehension) and expressive (speaking) skills, and includes different forms (phonology, morphology, syntax), contents (vocabulary, semantics) and uses (pragmatic/social use of language).
So a language disorder is a trouble in understanding and/or communicating. There are two kinds of language disorders (receptive and expressive). But it is quite common to have both at the same time. More specifically, if your child is diagnosed with a language disorder, he might have problems following directions and understanding questions, and/or trouble learning new words or saying sentences.