1. Second language acquisition is the process by which people learn a second language. Second-language
acquisition (SLA) is also the name of the scientific discipline devoted to studying that process. Second
language refers to any language learned in addition to a person's first language; although the concept is
named second language acquisition, it can also incorporate the learning of third, fourth or subsequent
languages. Second-language acquisition refers to what learners do; it does not refer to practices in
language teaching.
Principles of Second Language Acquisition (SLA) are:
1. Language is Changeable and Vocabulary has an Important Role in Acquisition; All
languages are a tool which can be manipulated to serve the needs of those who use it. But
language is always changeable; it caused there is no language can develop without the
development of the society. So that when the society develop, certaintly language also develop.
2. Language Acquisition is also Cultural Acquisition; Language is the composition of
culture, is the load of culture. In short, language and culture are merged tightly.
3. Language Acquisition is A Long–term Process; We know that language acquisition is
inseparable from its culture and culture acquisition can't be acquired in a short time. So language
acquisition needs a reasonably long time.
4. Motivation is the Stimulation of Second Language Acquisition; Motivation is the
generator to do something. Good motivation can improve work or study of something. Language
acquisition is not a simple job but an affordable work, which needs long and sometimes painful
process.
5. Native Language Proficiency is of Benefit to Second Language Acquisition; In the
world, different nations normally have different languages; however, any language proficiency
including native language surely contributes to second language acquisition because there is no
language that exists without any rules. One can use one rule in this language and that at some
cases.
6. Social Factors Affect the Second Language Acquisition; The social factors affect our
lives and also have a great impact on second language acquisition but probably do not influence it
directly.
7. Individual Acquirer Differences Differ in Second Language Acquisition: Cognitive
style is a term used to refer to the manner in which people perceive, conceptualize, organize, and
recall information. Each person is considered to have a more or less consistent mode of cognitive
functioning. “Open” or “close” person in character is different from acquisition of language.
Therories of Second language Acquisition (SLA):
1. The Acculturation Model: Second language acquisition is just one aspect of
acculturation and the degree to which a learner acculturates to the terget language group will
control the degree to which he acquires the second language.(Schumann 1978:34)
2. The Nativization Model: Andersen sees two general forces; nativization and
denativization. Nativization consists of assimilation while denativization involves accomodation.
The acculturation and nativist models focus on the power mechanisms of SLA
3. Accomodation Theory: This theory does not explain assembly mechanisms nor account
for the developmental sequence. The strenght of accomodation theory is that it encompasses
language acquisition and language use within a single framework. This theory provides an
explanation of language-learner language variability.

2. 4. Discourse Theory: Through communicating with other people, children accomplish
actions in the world and develop the rules of language structure and use. This view of how the
development takes place is called discourse theory. The discourse theory does not address the
nature of the learner strategies responsible for SLA.
5. The Monitor Model: Causative variables taken into account in the Monitor Model. The
monitor, the only evidence for monitoring lies in the language user's own account of trying to
apply explicit rules ( e.g Cohen and Robbins 1976) and Krashen's treatment of variability.
6. The Variable Competence Model: The process of language use is to be understood in
terms of the distnction between linguistic knowledge and the ability to make use of this
knowledge. The variable competence model of SLA attemps to account for the availability of
languages learners and the external and internal processes responsible for SLA.
7. The universal hypothesis: The universal hypothesis provides an interesting account of
how the languages properties of the target language and the learner's first language may influence
the course development.
8. A neurofucntional theory: A neurofucntional perspective on language attempts to
characterize the neurolinguistic information processing systems responsible for the development
and use of language. Neurofucntional accounts of SLA have considered the contribution of The
left hemisphere and The right hemisphere of the brain. Right hemisphere is responsible for the
storing and processing of formulaic speech. Left hemisphere functioning, in general the left
hemisphere is asscociated with the creative language use, including syntatic and semantic
processing and the motor operations involved in speaking and writing.
Practice of Second Language Acquisition:
1. Learning in The Classroom. Teacher need the resources of an authentic language
learning. It is especially needed when we study a second language in our own country. Sources of
learning the language used should be authentic in terms of pronunciation, intonation, accent and
idiom. In addition the teacher / the school is required to provide newspapers and magazines in
both languages because it is a valid reading of two sources and always provide the latest
information about the culture of both.
2. Learning Self-taught. This method can be done in a way to buy a CD or DVD learning a
second language that many are sold in bookstores / tapes or can be ordered online via the Internet.
Fundamental weakness of this learning method is the absence of accompanying teachers, so that
when students need to ask, no one can answer.
3. The Exchange of Langauge. Learning a second language by using this method requires
students to find native speakers who are studying a second language and who want to learn the
mother tongue or first language of students, so the two can teach each other their respective
languages. This can be done by accessing several sites on the Internet that offer these services
4. Traveled and Lived for Some Time Abroad. By traveling abroad or even the
opportunity to stay for some time abroad, students will be able to understand the culture of local
people. He can see and realize the similarities nor the differences between people and the culture
of the nation's culture whose language is being learned.