There is another way in which knowledge of language and real-world experience are kept apart in the minds of children; they do not always base their understanding of language on what they have come to know from experience. For example, children do not combine the words of the sentence 'Mice chase cats' in a way that conforms with their experience; if they did, they would understand it to mean that cats chase mice, not the reverse. In other words, children are able to tell when sentences are false, as well as when they are true. This means that children use their knowledge of language structure in comprehending sentences, even if it means ignoring their wishes and the beliefs they have formed about the world around them.