The term children's communication is used to describe how humans communicate in the first years of their lives. Some use the term more broadly and include in it in the first forms of interaction with the mother when the infant feels the warmth and the odors of the mother's body, hears her voice and feels the comfort of her arms. However, according to Catherine E. Snow in Children's Language and Communication (1979), this interaction lacks two important characteristics in order to be considered communication, namely intentionality and intersubjectivity. In the mother/infant interaction the sender does not produce signals with the intention to pass information to the receiver or with the expectation that the signals will be interpreted as they were intended.
Communication, including children's communication, serves a variety of functions. One of the main functions is informing, meaning that the process is focused on conveying certain information. In addition, a person can use communication to express feelings or to control or persuade another person. Communication can also be used to perform rituals in, for example, religious rituals, ceremonies or other predictable situations such as exchanging standardized greetings with an acquaintance on the street. Another function of communication is imagining, which includes all forms of pretending, storytelling, acting and most other forms of play. Messages that serve the imagining function are the same as other messages but they also convey the information that the message is not real.
Communication is considered to be an innate-learned behavior, meaning behavior that is transmitted genetically but its appearance is triggered by the environment. The development of speech in children is to be considered a biological event that is as natural to a child as learning to walk, according to Robert Hopper and Rita C. Naremore in Children's Speech: A Practical Introduction to Communication Development (1978). However, speech development is also very much dependent on the environment. Although children can learn to speak in almost any environment, they need supportive environments in order to learn to read, write or speak eloquently. Language behavior in children develops in parallel with motor functions, and the basic psychological abilities of attention, perception and conceptualization serve as a foundation of language.
Children's speech can convey both semantic meaning (the relation between words and concepts) and pragmatic meaning (the relation between words and their effects). This means that children use words and sentences to refer to an object or concept but also to fulfill some function – for example, a child may say "Cookie!" both to refer to a real cookie and to ask the mother to give him or her a cookie. According to Hopper and Naremore, "it may well be that the motivation for all language learning comes out of the child's increasing appreciation of words' effects on the environment."
Like human communication in general, children's communication can be divided in two categories – verbal (using words as signals) and nonverbal (using other signals than words). Nonverbal communication in children develops in parallel with verbal communication. However, the first attempts to communicate are mostly based on nonverbal signal – for example, a toddler will usually point at something if he or she wants to get it. Over time children learn to use a wide variety of gestures and facial expressions that come to express meanings just as words do. Nonverbal communication is sophisticated and useful but it has some limitations. For example, nonverbal signals are most often used to communicate emotions and they are not very useful when people discuss abstract concepts.
Children sometimes have communication problems that may differ depending on the cause and on the symptoms, ranging from simple sound substitutions to the inability to understand or use language to the inability to use the oral-motor mechanism for speech and feeding. A child is said to have delayed communication development when he or she's acquires speech and/or language skills are at a noticeably slower pace that his or hers peers. Sometimes the child's receptive (understanding) language skills are better than his or her expressive (speaking) skills but this is not always the case.
Speech disorders refer to difficulties producing speech sounds or problems with voice quality, while language disorders mean impaired ability to understand and/or use words in context. Speech and language disorders may be a result of hearing loss, neurological disorders, brain injury, mental retardation, drug abuse and/or physical impairments such as cleft lip or palate.