With respect to the conversation, Quan’s problem is that he is terribly nervous about exams. So, he feels dizzy and hot all ove

Professor
    Today we are going to discuss one important linguistic hypothesis, that is, the critical period hypothesis. Many discussions about first language acquisition center on the question of whether there is critical period for language acquisition, that is, a biologically determined period of life when language can be acquired more easily and beyond which time language is increasingly difficult to acquire. According to this hypothesis, it may be concluded that the critical age for full first-language learning lies somewhat under 12 and 13 years and over 6 and 7. Plenty of evidence has been found to support this hypothesis.
    For example, an American girl named Genie was 13 years old when she was found. She had been locked by her father in a dark room since about age 2 and had not talked to anyone until she was 13 when she was found by the police. Although many linguists had made great efforts to teach her language, she was eventually able to learn a limited vocabulary, but was never able to grasp on to language as a whole. Another popular example is Helen Keller. She was blind and deaf since infancy at 19 months and began to learn language at the age of seven. The result is that she grasped the language and learned it quite well. As shown in these two examples, when Genie began to learn the language, she was already 13 years old. According to the critical period hypothesis, she already passed the critical period of learning languages. However, when Helen Keller started to learn languages, she was only 7 years old. So, she was still under the critical age of learning languages. So, she was successful in learning languages.