Language development skills are the way children learn to understand and communicate at an early age. The stages of language development are the same in all humans. However, the age and pace that a child learns language is different for each individual. As the child gets older, language learning becomes more difficult.
Most language development skills are learned in the first three years of life when the brain is still developing. Some believe language development skills start as early as when the child is a fetus and can recognize its mother's voice and speech patterns. Language development skills start out simple with babbling and mimicry. By 9 months a baby is usually able to understand simple words and commands, and may even be able to say a few words. As the child gets older he starts to combine words and form simple sentences. At age five the child's language development skills should be similar to that of an adult.
There are several theories about how language development skills are acquired. One theory is that language is learned through reinforcement and imitation. An example of this would be when a parent rephrases what the child has said. Another theory is that language is unique to humans only. This theory states that all children already know how to produce sentences once vocabulary is learned. The last theory consists of two parts, the first being that the brain is able to detect patterns such as in speech. And the second is the desire to be understood by others as well as understanding others. This would suggest that social interaction is very important in acquiring language development skills.