What is Language Acquisition?

First language acquisition refers to the way children learn their native language. Second language acquisition refers to the learning of another language or languages besides the native language.

For children learning their native language, linguistic competence develops in stages, from babbling to one word to two word, then telegraphic speech. Babbling is now considered the earliest form of language acquisition because infants will produce sounds based on what language input they receive. One word sentences (holophrastic speech) are generally monosyllabic in consonant-vowel clusters. During two word stage, there are no syntactic or morphological markers, no inflections for plural or past tense, and pronouns are rare, but the intonation contour extends over the whole utterance. Telegraphic speech lacks function words and only carries the open class content words, so that the sentences sound like a telegram.

Three theories
The three theories of language acquisition: imitation, reinforcement and analogy, do not explain very well how children acquire language. Imitation does not work because children produce sentences never heard before, such as "cat stand up table." Even when they try to imitate adult speech, children cannot generate the same sentences because of their limited grammar. And children who are unable to speak still learn and understand the language, so that when they overcome their speech impairment they immediately begin speaking the language. Reinforcement also does not work because it actually seldomly occurs and when it does, the reinforcement is correcting pronunciation or truthfulness, and not grammar. A sentence such as "apples are purple" would be corrected more often because it is not true, as compared to a sentence such as "apples is red" regardless of the grammar. Analogy also cannot explain language acquisition. Analogy involves the formation of sentences or phrases by using other sentences as samples. If a child hears the sentence, "I painted a red barn," he can say, by analogy, "I painted a blue barn." Yet if he hears the sentence, "I painted a barn red," he cannot say "I saw a barn red." The analogy did not work this time, and this is not a sentence of English.

Acquisitions
Phonology: A child's error in pronunciation is not random, but rule-governed. Typical phonological rules include: consonant cluster simplification (spoon becomes poon), devoicing of final consonants (dog becomes dok), voicing of initial consonants (truck becomes druck), and consonant harmony (doggy becomes goggy, or big becomes gig.)

Morphology: An overgeneralization of constructed rules is shown when children treat irregular verbs and nouns as regular. Instead of went as the past tense of go, children use goed because the regular verbs add an -ed ending to form the past tense. Similarly, children use gooses as the plural of goose instead of geese, because regular nouns add an -s in the plural.

The "Innateness Hypothesis" of child language acquisition, proposed by Noam Chomsky, states that the human species is pre-wired to acquire language, and that the kind of language is also determined. Many factors have led to this hypothesis such as the ease and rapidity of language acquisition despite impoverished input as well as the uniformity of languages. All children will learn a language, and children will also learn more than one language if they are exposed to it. Children follow the same general stages when learning a language, although the linguistic input is widely varied.

The poverty of the stimulus states that children seem to learn or know the aspects of grammar for which they receive no information. In addition, children do not produce sentences that could not be sentences in some human language. The principles of Universal Grammar underlie the specific grammars of all languages and determine the class of languages that can be acquired unconsciously without instruction. It is the genetically determined faculty of the left hemisphere, and there is little doubt that the brain is specially equipped for acquisition of human language.

The "Critical Age Hypothesis" suggests that there is a critical age for language acquisition without the need for special teaching or learning. During this critical period, language learning proceeds quickly and easily. After this period, the acquisition of grammar is difficult, and for some people, never fully achieved. Cases of children reared in social isolation have been used for testing the critical age hypothesis. None of the children who had little human contact were able to speak any language once reintroduced into society. Even the children who received linguistic input after being reintroduced to society were unable to fully develop language skills. These cases of isolated children, and of deaf children, show that humans cannot fully acquire any language to which they are exposed unless they are within the critical age. Beyond this age, humans are unable to acquire much of syntax and inflectional morphology. At least for humans, this critical age does not pertain to all of language, but to specific parts of the grammar.

Second Language Acquisition Teaching Methods
Grammar-translation: the student memorizes words, inflected words, and syntactic rules and uses them to translate from native to target language and vice versa; most commonly used method in schools because it does not require teacher to be fluent; however, least effective method of teaching
Direct method: the native language is not used at all in the classroom, and the student must learn the new language without formal instruction; based on theories of first language acquisition
Audio-lingual: heavy use of dialogs and audio, based on the assumption that language learning is acquired mainly through imitation, repetition, and reinforcement; influenced by psychology
Natural Approach: emphasis on vocabulary and not grammar; focus on meaning, not form; use of authentic materials instead of textbook
Silent Way: teachers remain passive observers while students learn, which is a process of personal growth; no grammatical explanation or modeling by the teacher
Total Physical Response: students play active role as listener and performer, must respond to imperative drills with physical action
Suggestopedia: students always remain comfortable and relaxed and learn through memorization of meaningful texts, although the goal is understanding
Community Language Learning: materials are developed as course progresses and teacher understands what students need and want to learn; learning involves the whole person and language is seen as more than just communication
Community Language Teaching: incorporates all components of language and helps students with various learning styles; use of communication-based activities with authentic materials, needs of learner are taken into consideration when planning topics and objectives

Four skill areas
The four skill areas of learning a foreign language need to be addressed consistently and continually. Good lesson plans incorporate all four: Listening, Speaking, Reading (and Vocabulary), and Writing (and Grammar). Native speakers do not learn the skill areas separately, nor do they use them separately, so they shouldn’t be taught separately. However, it is easy to fall into the trap of teaching about the language, instead of actually teaching the language.