there is often a spurt of vocabulary acquisition during the second year. Early words are acquired at a rate of one to three per week; in many cases the rate may suddenly increase to eight to ten new word per week, after 40 or so words have been learnt. However, some children show a more steady rate of vocabulary acquisition during these early stages. During the second year, word combinations begin to appear. The rate of vocabulary acquisition accelerates in the third year and beyond: a plausible estimate would be an average of ten words a day during pre-shool and elementary school years. At about the age of two, children first begin to use grammatical elements. In English, this includes finite auxiliaries ( is, was ), verbal tense and agreement affixes, nominative pronouns, and determines. Over a year to a year and a half, sentences get longer, grammatical elements are less often omitted and less often inserted incorrectly, and multiple-clause sentences become commoner
đang được dịch, vui lòng đợi..
