Language learning begins with listening. Individual children vary greatly in the amount of listening they do before they start speaking, and late starters are often long listeners. Most children will "obey" spoken instructions some time before they Can speak, though the word "obey" is hardly accurate as a description of the eager and delighted cooperation usually shown by the child. Before they can speak, many children will also ask questions by gestures and by making questioning noises.
Any attempt to trace the development from the noises babies make to their first spoken words leads to considerable difficulties. It is agreed that they enjoy making noises, and that during the first few months one or two noises sort themselves out as particularly indicative of delight, distress, sociability, and so on. But since these cannot be said to show the baby’s intention to communicate, they can hardly be regarded as early forms of language. It is agreed, too, that from about three months they play with sounds for enjoyment, and that by six months they are able to add new sounds to their store. This self-imitation leads on to deliberate imitation of sounds made or words spoken to them by other people. The problem then arisen so to the point at which one can say that these imitations can be considered as speech.
It is a problem we need not get our teeth into. The meaning of a word depends on what a particular person means by it in a particular ,situation and it is clear that what a child means by a word will change as he gains more experience of the world. Thus the use,at say seven months, of "mama" as a greeting for his mother cannot be dismissed as a meaningless sound simply because he also uses it at other times for his father, his dog, or anything else he likes.
Playful and apparently meaningless imitation of what other people say continues after the child has begun to speak for himself. I doubt, however; whether anything is gained when parents cash in on this ability in an attempt to teach new sounds. (370w)
How many months old does child play with sounds not only for enjoyment

At 16 students in England and Wales take GCSE examinations. These examinations are taken by students of all levels of ability in any of a range of subjects and may involve a final examination ,an assessment of work done during the two-year course, or both of these things. At 18 some students taking A-level examinations, usually in not more than 3 subjects. It is necessary to have A-levels in order to go to a university or polytechnic.
In Scotland students take the SCE examinations. A year later, they can take examinations called HIGHERS, after which they can either go straight to a university or spend a further year at school and take the Certificate of Sixth Year Studies. In Scotland the university system is different to that in England and Wales. Courses usually last four years rather than three and students study a larger number of subjects as part of their degree.
In the US school examinations are not as important as they are in Britain. Students in High Schools do have exams at the end of their last two years, but these final exams are considered along with the work that the students have done during the school years.
Social events and ceremonies
In American high schools there is a formal ceremony for Graduation. Students wear a special cap and gown and receive a diploma from the head of the school. Students often buy a class ring to wear, and a yearbook, containing pictures of their friends and teachers. There are also special social events at American schools. Sports events are popular, and cheer leaders lead the school in supporting the school team and singing the school song. At the end of their junior year, at age 17 or 18,students hold parties in the evening. The girls wear long evening dresses and the boys wear tuxedos(晚礼服).
In Britain, there are no formal dances or social occasions associated with school life. Some schools have SPEECH DAY at the end of the school year when prizes are given to the best students and speeches are made by the head teacher and sometimes an invited guest. However, in many British schools students and teachers organize informal dances for the older students.