Outline the processes by which children learn to use language.

During the prelinguistic stage, infants lay the groundwork for language without uttering actual words. This phase spans roughly the first year of life, where babies engage in cooing and babbling. These are not random noises; they are vital in developing the phonetic building blocks of their native language.

Cooing, which typically starts around two months old, consists of comfortable, vowel-like sounds. By the time they reach six months, infants begin babbling, which is the combination of consonants and vowels, like 'ba-ba' or 'ma-ma'. While these may not form actual words, they are critical exercises in vocalization and auditory processing that set the stage for true language development.

The one-word, or holophrastic, stage is a fascinating period in a child's language acquisition journey, typically occurring around 10 to 13 months of age. It's during this stage that children start to articulate single words which carry complex meanings or intentions, much like an entire sentence would for adults.

For instance, when a toddler exclaims 'milk', it could mean 'I want milk' or even 'I see milk'. This stage showcases a significant cognitive leap as children start to associate words with objects, desires, and people. Understanding this, adults usually interpret the context to respond appropriately, aiding the learning process. This stage sets the foundation for more complex language structures that will follow.

As children approach their second birthday, their linguistic abilities expand into what is known as the two-word stage. This leap is characterized by the combination of two words to express a rudimentary sentence—reflecting an emerging grasp of syntax and grammar.

Expressions like 'baby sleep' or 'more cookie' are common examples where nouns are combined with verbs or adjectives to convey a clear intention or observation. These utterances follow a logical grammatical structure and reveal children’s cognitive development in understanding and applying language rules. It's a critical stepping-stone that precedes more complex sentence formation.

The telegraphic stage of language acquisition typically unfolds between the ages of 2 and 3. During this stage, toddlers begin using short and precise sentences that omit non-essential words, mirroring the succinctness of telegrams.

Sentences like 'Mommy give ball' or 'Daddy go work' are hallmarks of this stage. These sentences, while grammatically incomplete, effectively communicate the child's thoughts. Telegraphic speech indicates a deeper understanding of language; children know which words are critical to get their point across. This economical use of language typically precedes the development of more complex sentences that include 'little' words like articles and prepositions that will enrich their communication.

Language development in children is a gradual process marked by several milestones that indicate the growing complexity of their linguistic skills. These milestones range from the prelinguistic gurgles and coos of infancy, when understanding begins, to the sophisticated, full sentences that more closely resemble adult speech by around age five.

Key milestones include the transition from babbling to the one-word and two-word stages, where children begin to communicate effectively with others. Important to note is that children don't suddenly stop one stage and start another; rather, there is a significant overlap where elements of different stages co-exist. These milestones are often broad; children may vary in the age at which they hit them, influenced by factors such as environment, exposure, and individual differences. Observing these milestones offers parents and educators insight into a child's development and can highlight when extra support may be beneficial.