Early on in the study of grammar, we come upon a concept which is essential to understand: that a group of words can act as a single part of speech. This one idea will in one fell swoop reduce the complexity of a sentence we want to change, because we’re no longer trying to account for every last word, but we’re seeing instead the larger and fewer sections of phrases and clauses, each of which stands as a single part of speech. Here’s how it works.
Let’s begin with this simple sentence: We took a walk in the woods yesterday. Revising often means rearranging, so if we want to consider how else we might present the ideas of this sentence to our readers, do we assume first that we are dealing with eight individual words? That, long experience tells me, is the first mistake most beginners (and those beginning again) make in trying to understand the grammar of a sentence. It’s true that every single word must have a role to play, but not every role is of the same importance at the same time. Some words carry an obvious meaning: we means a number of us, and woods means that dense stand of trees over there. But a or in? We want, certainly, to be able to understand ultimately how every word is functioning in a sentence, but not necessarily all at once, and certainly not as we first approach a sentence to revise.
So instead of preparing to do battle with each individual word in the sentence, let’s try welcoming it with a wider analytical embrace. Read it first from capital letter to period, and then divide it into the two large sections every sentence must have at least one of: subject and predicate. Thus, this first division of We | took a walk in the woods yesterday, would show us that, after the subject we, the bulk of the statement lies in the predicate, that part of a clause which includes the verb and all the other elements that build out the circumstances of the scene. We can count the predicate here, though, not as seven words, but as two single words plus two phrases: took (a walk) (in the woods) yesterday. A phrase is a group of words without a subject and verb, and by parenthesizing the phrases like this, we reduce our project to understand the structure of this sentence from seven steps to four.
The first phrase we encounter is simple enough. The indefinite article a is an adjective that works with the noun walk, and so we can quickly and correctly group those two words together and see that this phrase stands as the direct object of the transitive verb took: two words, one phrase, one grammatical function. The next word, in, is a preposition, and we know that a preposition must always have an object, which will most often be the first noun after the preposition. A preposition begins a phrase which ends with its object, and that phrase will include any word between the preposition and object as well. Thus, in the woods is a prepositional phrase, and since it—the phrase in its entirety, not any single word of the phrase alone—answers the question where?, we understand that element to be an adverbial phrase. Finally, we see the single word yesterday, which answers the question when?, and so we see another adverb, this time in the form of a single word.
Again, by seeing a group of words acting as one syntactical unit (the fancy word for that is syntagma), we make it much easier to uncouple the components and rearrange them to change the manner of our statement. By seeing the four words in the woods yesterday really as two elements (one phrase and one single word), we give ourselves the chance to consider putting the temporal adverb yesterday at the beginning of the sentence: Yesterday we took a walk in the woods. Or perhaps after the direct object: We took a walk yesterday in the woods. Or if we are in a more reflective mood, between the verb and its object: We took yesterday a walk in the woods. Or if we are drafting a poem, perhaps even this: We yesterday took a walk in the woods.
All of these choices present themselves to our revising eye when we can see structure. Here, we have not done anything directly with the prepositional phrase in the woods, but we have done many things with the single word yesterday, which came to our attention after seeing the prepositional phrase separate from it. But that prepositional phrase itself opens even more possibilities. If we wanted to stay in our poetic mood to see what might be seen in a very different (but very real) frame of mind, we could come next upon an entirely new height of structural possibilities: In the woods yesterday, we took a walk. Or, We yesterday in the woods took a walk. Or even, A walk we took yesterday in the woods.
After studying grammar to write more clearly, we can study it to reflect more deeply on what we perceive in the world about us, moving from factual statement to poetic evocation. Both, however, rely on structure, the heart of the art of language.