Acquiring a second language is a goal many adults set for themselves. Students have the ability to take foreign language courses early on in their education, but not many adults who attended school years ago had that option. The level of ease or difficulty in learning a second language is dependent on the stage of brain development and the style of learning. There are different options for learning a second language, and it can be most effective at a young age. Children who are introduced to the second language within their first year of life are much more likely to become fluent speakers of the language. By the age of ten to twelve months, the brain is already beginning to lose its ability to discriminate sounds between its native and nonnative languages (Sousa, 2006). The reality of this fact is that you would need to start teaching the child the second language as they are learning the first. Learning a language early has a direct effect on the presence of an accent and the ability for the speaker to be proficient. As a child ages, the brain recognizes sounds and can distinguish those that are foreign making it more difficult to introduce the words and meanings into their thinking.
Studies have shown that people who started speaking between ages of 8 and 10 have about 80 percent of the proficiency of native speakers; those who started between the ages of 11 and 15 spoke with only half the proficiency, and those who started after age 17 had only 15 percent (Sousa, 2006). This is why it can be much more difficult for an adult to become skilled at a second language. By the time a person is an adult, they have already learned the importance of grammar and the rules of their native language which can interfere with the syntax of the second language. This is an example of negative transfer, where the previously learned information negatively impacts the brain from learning new skills. Adults must focus more and have
References: Genesee, F. (December 2000). Brain Research: Implications for Second Language Learning Munnoz, Carmen. (2011). Input and Long-term Effects of Starting Age in Foreign Language Learning Sparks, Richard L.; Humbach, Nancy; Patton, Jon. (2011) Subcomponents of Second- Language Aptitude and Second-Language Proficiency Stein, Miriam Ph.D. (May 1999) "The Bridge: From Research to Practice: Developing Oral Proficiency in the Immersion Classroom" ACIE Newsletter, Volume 2, Number 3