Notes

I. Introduction
First language (L1) is a species-specific behavior. It is true that conditioned primates are able to react to human speech, or acquire gestures offered in repetition or reproduction. However, these reactions can not be compared with human with tremendous grammar skills. Although primates are clearly able to communicate with each other through relatively complex visual signs and are also capable of relatively differentiated linguistic communication by means of the production of sounds, they are not able to abstract or generalize. Animal languages like the signaling of a food source with respect to the level of sunshine by the dancing of bees can not be compared with the linguistic complexity of the human language. The use of arbitrary symbols is also a special feature of the human language.
Children learn their first language within a limited timeframe, relatively independent of the conditions of language acquisition and the different quality of the input. After approximately 4-5 years, children can implement the language to be learned correctly and have acquired the majority of grammatical structures and the vocabulary sufficient for communication. The first language follows specific, extra-linguistic patterns. Comparing different children from different language communities, one finds certain invariant patterns of language acquisition. Thus, all children begin to slur at about the same time, and the stages in terms of semantic-lexical and morphological-syntactic abilities are also very similar. L1 is performed without explicit learning or without instruction or classes. It is true that the input plays an important role in the acquisition of the language, but parents or collocutor persons do not need to give information to children, for example, on how to form grammatically well-formed sentences. The L1 is acquired in critical stages. If the sensitive or critical stages of the first-language acquisition are passed without input, for example, as in the case of a high degree hearing loss patient, a first language acquisition is no longer possible without problems. Such critical stages are indicators of an innate behavior or an innate acquisition mechanism.
The first language is often used as the synonym for the mother tongue and it unnecessarily means the chronologically first learned or the everyday language. The second language is often learned as an everyday language for the non-family environment. The basic difference between first and second language acquisition is that the learner uses grammar that does not comply with the target language. One can also differentiate between the controlled and the uncontrolled second language acquisition: The controlled second language acquisition is supported by instruction, the uncontrolled is half autonomous in everyday life and serves the multicultural purposes.
II. Literature Review
As Ipek H. (2009) stated “Various theories are put forward to describe first language (L1) acquisition and second language (L2) acquisition. In order to understand the nature of L1 and L2 language acquisition, various aspects were examined, compared, and contrasted.” Since the 1940s the second language acquisition has been the subject of numerous research and led to the development of the many approaches. Some of those approaches have been playing an incredibly important role in language education. Even though those approaches have some similar purposes or the same aspects, they also have some differences that distinguish them from each other.
Contrastive Analysis
Many aspects and factors such as comprehensible input, personality, age, motivation, language transfer, linguistic inference, learning environment etc. influence the linguistic performance of language learners. In order to understand the truth, many aspects were examined and proposed with some main approaches. In the Contrastive Analysis (CA) which is an approach to SLA, the main purpose is to predict and understand the problems of language learners. This is done by comparing two languages regarding differences and similarities. CA mainly deals with pedagogical aspects of second language acquisition. Robert Lado is the first one who started serious studies on Contrastive Analysis in 1957. Main motive behind CA is pedagogy.
Error Analysis
Nonetheless, this pedagogical aim has changed in Error Analysis which is an approach that was based on the analysis and description of actual learner errors in second language acquisition. This approach is different than CA in terms of main focuses. In CA main focus was on the pedagogical aspects of second language acquisition. Educational concerns of CA were replaced by the focuses that are on learning process and errors of actual learners. Khansir A. A. (2012) stated that unlike CA, “EA provides evidence for a much more complex view of the learning process- one in which the learner is seen as an active participant in the formation of and revision of hypotheses regarding the rules of the target language.”

Interlanguage
On the other hand, “Larry Selinker (1972) introduced the Interlanguage (IL) to refer to the intermediate states (or interim grammars) of a learner’s language as it moves toward the target L2.” as it was stated by Saville-Troike (2012). Since interlanguage is the hypothesis based on the essentials and fundamental notions in EA, some similarities and of course some differences arise between the two approaches. For instance, they both share the aim of analyzing the two languages but IL relatively deals with the cognitive processes and interim grammars between the L1 and L2 during second language acquisiton.
Morpheme Order Studies
As it was mentioned by Kwon (2005) “The history of Morpheme Order Studies dates back to R. Brown’s (1973) study of three children who were native speakers of American English. This longitudinal study is widely recognized as the starting point of the acquisition order research.” According to the Morpheme Order Studies, while acquiring the grammatical rules or structures of a certain language, learner's undergo a development order or phase. This development order can show differences among learners according to some factors. For instance, learners who are exposed to these grammatical structures or practice and implement these rules into a natural use could acquire the grammer faster than the ones who do not implement. When it comes to talk about what is inferred from the claims resulted with Morpheme Order Studies, it could easily be said that innate abilities for language acquisition might be used even by adult learners.
Monitor Model
In 1978, Stephen Krashen proposed an approach called Monitor Model. It is based on the explanation the relationship between the learning and acquisition. According to Ricardo Schütz (1998) concious learning does not have a considerable role in second language acquisition. To the point of Krashen's view, Schütz continues like that; “There is individual variation among language learners with regard to 'monitor' use. Krashen distinguishes learners that use the 'monitor' always; those who have not learned or who prefer not to use their conscious knowledge; and those that use the 'monitor' appropriately.” Schültz also thinks that reason behind the lack of self-confidence could be stemmed from using “monitor” frequently. And it might be inferred that Monitor Model could have led to other approaches to be based on these claims on explanation of the relationship between the learning and acquisition.
Universal Grammar
“Universal Grammar (UG) is a linguistic theory, proposed by Noam Chomsky, that argues that the ability to learn language is innate, distinctly human and distinct from all other aspects of human cognition.” as it was mentioned by Mark Ettlinger (2014). Universal Grammar generally means what is common to all natural languages. Such universal (common features) can be characteristics of the languages themselves, innate mechanisms of learners in language acquisition. Universal Grammar has shown some developments on its concepts which were taken place by the Principles and Parameters framework and also Minimalist Program. Differently from other approaches, Universal Grammar has led to this reconceptualization.
Systemic Linguistics
M. A. K. Halliday developed this model in the late 1950s to analyze the languages with a regard to their interrelated systems of choices that are available for conveying the meaning as it took place in the book “Introducing Second Language Acquisition” by Saville-Troike. The earlier studies have taken an internal focus on languages during the conceptualizing theories or proposing new ideas by different researchers, whereas Systemic Linguistics was based on focusing on the external factors and influences. In contrast to earlier approaches to SLA, Systemic Linguistics deals with some different factors such as the circumstances of the use of different language structures and some other extralinguistic entities etc. Thus, taking an external focus on language learning is the main characteristic that makes Functional Approaches like Systemic Linguistics different.
Funtional Typology
The next approach is socalled Functional Typology which has a functional framework that could be considered as similar with Systemic Linguistics. Functional Typology is based on the comparison of many different languages in the world. As it can be understood from its name, this approach mainly deals with functions of language like structure, meaning, and use. Functional Typology can be contrasted to its earlier counterpart which is Contrastive Analysis, because CA has direct counter aims towards Functional Typology. Functional Typology is based on a comparison of a wide range of world languages. It is not merely comparing and contrasting two similar or different languages with one and other, but rather, it aims to point the differences between the languages or point the similarities between languages at different levels. (phonological level, syntactic level, pragmatic level, discourse level etc. On the contrary, CA arose with the aim of improving the quality of second language education. By comparing and contrasting the two languages, they try to predict learners problems and then they try to develop materials that are appropriate for the learners of a certain language. Main motive behind CA is pedagogy. But Functional Typology does not have that kind of purpose. FT is purely linguistic approach. It has nothing to do with educational or pedagogical purposes. It makes a comparison and then subsequently it categorizes languages according to their characteristic features in order to decide on the similarities and differences with the purpose of calculating and assessing the frequency or universality of types and patterns at distribution. For example, in different languages how people use certain linguistic entities while thinking of the upcoming expressions or when they get stuck. This is what Functional Typology deals with.