The Importance of Learning a Second Language 
INTRODUCTION: DESCRIBING AND EXPLAINING L2 ACQUISITION
Since its emergence some 20 years ago, the field of second language acquisition research has focused on two areas: the nature of the language acquisition process and the factors which affect language learners.
As we know second language acquisition focusses on the developing knowledge and use of a language by children and adults who already know at least one other language. Knowing this we can say that SLA has two main goals: description and explanation.
Description is about how second language proceeds. Explanation is the goal that identifies the external and internal factors which have influence in the process of acquisition. There are some external factors, the most common are the social context in which learning takes place and the input that learners receive, in this point, the input is very important because any language learning occurs without some input, it must facilitate the whole process. About internal factors we have to take into account the cognitive mechanism which enable learners to extract information about L2 from the input, in this case, learners can realize about some rules such as the plurality of verbs and the “s” for third person. Learners can use knowledge they already know to assimilate some unknown words because of lack of vocabulary, in this way, they can replace some words in order to communicate their ideas. Finally, internal factors have influence in how successful learners are; due to language aptitude is different for each person, some learners find the process easier than others.
Most people believe that children are better than adults when attempting to learn a second language. Factors involved in second-language acquisition can be divided into two kinds, the psychological and the social (as we can see in the two cases examples). Intellectual processing which is involved in the determination of grammatical structures and rules, memory which is essential for learning
Since its emergence some 20 years ago, the field of second language acquisition research has focused on two areas: the nature of the language acquisition process and the factors which affect language learners.
As we know second language acquisition focusses on the developing knowledge and use of a language by children and adults who already know at least one other language. Knowing this we can say that SLA has two main goals: description and explanation.
Description is about how second language proceeds. Explanation is the goal that identifies the external and internal factors which have influence in the process of acquisition. There are some external factors, the most common are the social context in which learning takes place and the input that learners receive, in this point, the input is very important because any language learning occurs without some input, it must facilitate the whole process. About internal factors we have to take into account the cognitive mechanism which enable learners to extract information about L2 from the input, in this case, learners can realize about some rules such as the plurality of verbs and the “s” for third person. Learners can use knowledge they already know to assimilate some unknown words because of lack of vocabulary, in this way, they can replace some words in order to communicate their ideas. Finally, internal factors have influence in how successful learners are; due to language aptitude is different for each person, some learners find the process easier than others.
Most people believe that children are better than adults when attempting to learn a second language. Factors involved in second-language acquisition can be divided into two kinds, the psychological and the social (as we can see in the two cases examples). Intellectual processing which is involved in the determination of grammatical structures and rules, memory which is essential for learning