ABSTRACT
This chapter concerns the rules governing the complex activity. A particular idea can lead eventually to speech without any written input. There is, therefore, no direct one-to-one correspondence between a particular written form and a particular pronunciation. Words that are frequent in the written language are more easily detected. This is not a property of the word as such: frequently-occurring words have no distinctive physical features. It is, rather, that for the words the detector becomes active on less evidence. There are two ways in which a written form can lead to understanding. The first is direct. By this route the visual form of a word (that is, its shape and its component letters) can be used to activate an area of the reader's knowledge. The second route is indirect and capitalizes on the fact that there are correspondences – albeit rather weak ones – existing between letters and sounds.
