The book presents the process of first and second language acquisition in children as well as the main principles of conventional and unconventional approaches and methods implemented in the general education as well as the language education of children. The long-term quantitative study described focused on the comparison of the results obtained by young learners taught English according to the Helen Doron Method in private courses and the results gained by young learners instructed according to the modern eclectic method at public primary school. The results were compared in such language areas and skills as vocabulary, grammar, language chunks, pronunciation, listening skill, speaking skill and a general level of language acquisition.