[Translation from English to Japanese ] So it is clear that, even in the case of "simple" words like"ball", the acqui...

So it is clear that, even in the case of "simple" words like"ball", the acquisition of word meaning it's not an understanding of the development of thought and language.
Thus it it's by no means so easy as one might suppose to give a straightforward answer to the question: how language it's a child's vocabulary, on average, at different ages?

よって、「ボール」のような「単純な」単語においても、言葉の意味を習得することは思考と言語の発達を理解することではない、というのは明らかだ。
そのため、年齢別の子どもの平均的な語彙はどのくらいか、という質問に対して明快な回答をすることは、決して思うほどに簡単ではない。