Sentence comprehension is more than a syntactically autonomous issue and relies on the clues that are not part of the grammar. This paper considers "world knowledge," in this case prior knowledge of the story being read, as one such clue. In section 1, "reversibility" of sentences is discussed. "Sentence ambiguity" is discussed in section 2. Section 3 is the experimental section that examines how world knowledge influences the interpretation of ambiguous sentences and affects linguistic development. The experiment was conducted to observe the fluctuation in subjects interpretation of ambiguous sentences and to analyze how knowledge of the story influences it. Sixty-five children in the Kyoto and Nara areas in Japan, aged 6-12, were given a strip of paper to read. After reading the strip of paper, the children were asked to act out what was written on the paper. The experiment showed that world knowledge plays an important role in sentence comprehension. It was concluded that world knowledge helps children in assigning an alternative structure they would not normally assign to the sentence. As a result of this, a child may become aware of the fact that a sentence can have more than one meaning. It is also concluded that the role of world knowledge seems to be related to maturation; younger children appear to be more influenced by world knowledge. (VWL)