1.2.1 The Lexicon
The first assumption we will make is that one of the things that a speaker of a language knows is facts about words. We know, for instance, how a given word is pronounced, what it means and where we can put it in a sentence with respect to other words. To take an example, the English word cat is known to be pronounced [kæt], is known to mean ‘a small, domesticated animal of meagre intelligence that says meow’ and is known to be able to fit into the marked slots in sentences (2), but not in those marked in (3):
| (2) | a | the cat slept |
| b | he fed Pete’s cat | |
| c | I tripped over a cat | |
| (3) | a | *the dog cat the mouse |
| b | *cat dog howled | |
| c | *the dog slept cat a kennel |
It is obvious that this knowledge is not predictable from anything. There is no reason why the object that we call a cat should be called a cat, as witnessed by the fact that other languages do not use this word to refer to the same object (e.g. macska (Hungarian), chat (French), Katze (German), gato (Spanish), quatus (Maltese) kot (Russian), kissa (Finnish), neko (Japanese), mao (Chinese), paka (Swahili)). Moreover, there is nothing about the pronunciation [kæt] that means that it must refer to this object: one can imagine a language in which the word pronounced [kæt] is used for almost anything else. This kind of linguistic knowledge is not ‘rule governed’, but is just arbitrary facts about particular languages.
Part of linguistic knowledge, therefore, is a matter of knowing brute fact. For each and every word of the language we speak it must be the case that we know how they are pronounced and what they mean. But this is different from our knowledge of sentences. For one thing, there are only a finite number of words in any given language and each speaker will normally operate with only a proportion of the total set of words that may be considered to belong to the language. Therefore, it is not problematic to assume that knowledge of words is just simply stored in our heads. Moreover, although it is possible, indeed it is fairly common, for new words to enter a language, it is usually impossible to know what a new word might mean without explicitly being told. For example, unless you had been told, it is not possible to know that the word wuthering found in the title of the novel by Emily Brontë is a Yorkshire word referring to the noise that a strong wind makes. With sentences, on the other hand, we know what they mean on first hearing without prior explanation. Thus, knowledge of words and knowledge of sentences seem to be two different things: knowledge of words is brute knowledge while knowledge of sentences involves knowing a system that enables us to produce and understand an infinite number of them (an I-language). Clearly, part of knowing what a sentence means involves knowing what the words that constitute it mean, but this is not everything: the meanings of the words three, two, dogs, cats, and bit simply do not add up to the meaning of the sentence three dogs bit two cats (if you think about it this sentence might mean that anything between two and six cats got bitten, which is not predictable from the meaning of the words).
Let us assume that these different types of linguistic knowledge are separate. We can call the part of I-language which is to do with words the Lexicon. This might be imagined as a kind of mental dictionary in which we store specific information about all the words that we use: how they are pronounced, what they mean, etc.