THE THREE DIMENSIONS OF GRAMMAR

Form, Meaning, Use
A way to capture the fact that grammatical structures have forms, meanings, and uses is to draw a pie chart with three wedges, one for form (which deals with accuracy), one for meaning (which relates to meaningfulness), and one for use (which deals with appropriateness). The arrows connecting the wedges indicate that the three dimensions are interconnected and that each dimension is always present. Nevertheless, as we will see later in this course, the three dimensions present different challenges to students. Because they are learned differently, they should be taught differently.
Take, for example, the English non-referential there. It is called non-referential because it doesn't really refer to anything. It occupies the subject position in a sentence. The true subject of the sentence, the one that determines the form of the verb, follows the verb, usually some form of the verb "to be." For example, in sentence 1 below, the true subject of the sentence is "a pencil," therefore, the verb "is" is singular. In sentence 2, the true subject of the sentence is "pencils"; therefore, its verb is the plural "are."
There is a pencil on the table.There are pencils on the table.
As I have said, grammar is about accuracy. If I were to scramble the words in sentence 1, the sentence would become ungrammatical.
*is a table pencil on the there (remember the asterisk is a symbol of a grammatically incorrect form)This is because its word order (also known as syntax) is mixed up. Sentence 3 is also ungrammatical. The true subject of this sentence is "a pencil," which in sentence 3 does not agree with the verb.
3.*There are a pencil on the table.It is not accurate in English to say "*a pencil are…" because the subject ("pencil") and the verb ("are") do not agree. The form of the subject is singular and the form of the verb is plural. It is true, therefore, that word order rules and rules of subject-verb agreement do relate to grammatical accuracy. However, that is not the whole story.
Let's compare the following:
4. There is a pencil on the table.5. It is a pencil on the table."There" might not refer to anything in particular, but that does not mean that it contributes no meaning. When it is in initial position in a sentence, as it is in sentence 4, the sentence asserts the existence of something and often includes a phrase that tells us of the location of that something.
Asserting the existence is different from the meaning of sentence 5 with "it" in subject position. Sentence 5 identifies an object, or distinguishes one object from another ("It is a pencil on the table, not a pen."). Thus, "there" can indeed be associated with a meaningIt is not uncommon for grammarians (people who study grammar) to talk about the form and meaning of a grammatical structure. However, it is less common, though no less important, to understand that there are considerations of use in grammar as well.
Compare the following two sentences:
6. There is a pencil on the table.7. A pencil is on the table.Take a minute to see if you can figure out the difference between them. It is not likely that they will both exist in English without there being some difference between them.
Both sentences are accurate in form because they follow word order rules and the rule of subject-verb agreement. Both sentences are meaningful. In fact, both mean more or less the same thing—they tell us about the existence of a pencil and its location. However, as I have just said, it is not likely for two structures in any language to have the same meaning and the same use, so there must be something distinctive about their use.
Well, imagine a situation where you need something to write with. You might tell someone, "I need something to write with." If the other person wishes to be helpful, he or she might say sentence 6, but probably not sentence 7. Can you figure out why?
The answer is because sentence 7 implies that you should have known that a pencil was on the table. If you had known this, of course, you would have simply picked up the pencil and not said anything. Therefore, 6 is more helpful and polite than 7 in this situation. This is because the function of "there" is to introduce new information—information that you would not expect your listener to have.
The point is that a pedagogical grammar (a subset of grammar rules used to teach grammar to language students) needs to explain not only how a grammar structure is formed and what it means, but also when to use it appropriately.
As I have already suggested, a way to display the three dimensions of grammar--form, meaning, and use--is to use a pie chart with the information about a grammatical structure in each wedge. Let's look at the form, meaning, and use of sentences with "there," and draw a pie chart with this information.
Can you see how helpful the pie chart can be? You can ask the three questions—How is it formed?; What does it mean?; When or why is it used? about any grammar structure. When you do so, you have a complete picture of the grammar structure: how it is formed, what it means, and when/why it is used. For the remainder of this lesson, we will investigate these three dimensions further.