What is the difference between a swimming instructor and a swimming instructor? You might think that a silly question, but look again. The difference lies in the word swimming, identical in spelling but different in grammar. Here’s a hint: in one of the phrases, the instructor might be swimming; in the other, the instructor must be swimming. Words that end with the suffix –ing are always best approached cautiously, and this one is no exception.

Let’s, though, figure this out. The suffix –ing creates two distinct grammatical species: a participle and a gerund. A participle is an adjective and a gerund is a noun, but unlike other simpler adjectives and nouns, these two are derived from verbs. The terminology of grammar recognizes this by more properly defining a participle as a verbal adjective and the gerund as a verbal noun, and since both have a verb in their parentage, they have the characteristic of action, or movement and change, in their representation. It is one thing to think of a tall man and another to think of a threatening man; both tall and threatening are adjectives, but the former describes a static quality, the latter a dynamic, dangerous quality.

Likewise with a noun. We may speak of a book on the table, and mean by that simple noun a static object set somewhere. Or, instead, we may speak of booking a reservation, in which case we are still talking about something, but the thing we are referring to is as much an action as it is an entity. And that is exactly what a gerund is: an action regarded as a thing, a thing which exists, however, only in the moment of its performance—just like living. Both the gerund and the participle, by virtue of their verbal lineage, bring a sense of action to the context in which they appear, and that can be a powerful tool in one’s writing kit.

If we take this quick review, then, to our original question, the meaning of the phrase swimming instructor will depend upon whether we regard swimming as a gerund or a participle. If a gerund, then we mean an instructor of swimming, someone who teaches someone else how to propel and keep afloat in water. A gerund is often recognized by inserting the phrase the act of: the word swimming, as a gerund, refers to the act of swimming, movement regarded as something while it’s being undertaken. If, however, we regard this same word in –ing as a participle, then the phrase means an instructor who is swimming. This instructor might teach math or science or painting, but in the moment being written about, this instructor is apparently doing something, namely, swimming. That participle serves to describe the instructor, to name a quality that appears only in some manner of movement.

Now the only curiosity we have to recognize here is this: when we construe swimming as a gerund and take the phrase to mean an instructor of swimming, aren’t we really using the gerund, which is a noun, as an adjective? We can very often find an adjective by asking the question what kind of?, so are we not really asking what kind of instructor this person is? In fact, we use nouns as adjectives all the time. If I say that my Wednesday schedule this week is crazy, I am using the noun Wednesday as an adjective to modify the noun schedule. We speak of farm equipment and aircraft noise abatement, where the nouns farm and aircraft and noise are all adjectives for the moment (in the second phrase, aircraft modifying noise and the two together modifying abatement). And so similarly the gerund swimming may also be understood as a noun qua adjective describing the noun instructor.

But after it’s all said and done, a swimming instructor is either an instructor of swimming or an instructor of something who happens to be swimming—sometimes even in the churning waters of grammar.

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So much depends on method. When we want to do something—and what we do with our mind is just as real as what we do with our hands—the way we begin can make all the difference, because where we launch out from will determine how we fare to our goal of understanding or making something. In writing, and more specifically in analyzing composition, there is a way to proceed which antidotes the natural tendency we have to look frantically around a sentence for some place to start. That haphazard manner almost never avails. So how do we enter upon the sure way to a grammatical answer?

Let’s say we’ve written a sentence like the following, and in reading it again we’re now wondering whether we should have one comma, two commas, or no commas at all: The cat, sitting sleepily on the stairs, leapt suddenly at the cicada. Like that cat, we have it in our human nature too to jump at something, and in trying to understand the construction and punctuation of a sentence, that can mean beginning with any word that seems to resemble a verb—because every sentence has a verb, right? Every formally complete sentence does have a verb (most often explicitly present, but sometimes merely implicitly so), but not every word that resembles a verb is a verb, much less the main verb of the sentence.

So because words can appear as something they’re not, it’s best in analyzing a sentence to begin at the beginning and end at the end, always finding first the skeletal center of the clause—the subject and its real verb. By real verb I mean what the grammarians call the finite verb, a word of action or identity which is specifically connected to a subject by real, or chronological, tense (among other verbal properties). In the sentence we’re looking at, the cat did something at a specific moment in time: it leapt, and so in combining those two words, we produce the frame, or skeleton, of the clause. Those two parts, subject and finite verb, constitute the center of grammatical gravity of the assertion.

But didn’t the cat also sit? And isn’t sit, therefore, also a verb? It’s true that the cat was sitting somewhere, but notice that the sentence does not include the verb was. We have only the participle sitting, and a participle is not a finite verb. A participle is built from a verb and it has time, but the time it represents is relative, not absolute or real or time according to the clock. Sitting is a present participle, and present in a relative context means contemporaneous to the real time of the finite verb. Thus, the cat that leapt at a certain moment in the past was doing something else at that past time, namely, sitting sleepily on the stairs; but since the participle sitting is not a finite verb, we cannot say that the sentence explicitly asserts that the cat was sitting—it only implies that by way of description.

Without having first determined the grammatical center of the sentence, we could have very likely been misled by the verbal impression of the participle, thinking that sitting was the verb of the clause. Since, though, we began our analysis correctly, that central point we discovered gave us an orientation which helped us see the subordinate position of sitting; we were not distracted, that is, by the verbal sense of that participle. And that same grammatical gravity can also help us with our original question about the commas. We must have two commas if any at all, because one marks the beginning and the other the end of the participial phrase sitting sleepily on the stairs. But does that phrase need to be set off by commas at all?

No, if it defines the cat that leapt (perhaps there were others in the vicinity); yes, if it merely describes more fully the only cat that leapt (there apparently being no other cats and so no need to define which particular cat leapt). That’s a lot to think about, and without proceeding first to the center of the sentence, so to speak—to the vantage point of subject and finite verb—we risk losing our grammatical balance, making good and basic questions more difficult than they really are if not taken up methodically.

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Contemplative traditions and meditative disciplines often describe thoughts as sticky. One thought glues itself to some other vaguely related thought that happens to come along, and before you know it, you’re stuck fast in a gooey and unshapely conceptual world of your own making, a ramble that takes you far from the simple, wise, and self-evident truth of things as they really are. In meditation, this is named the work of the ego; in the craft of writing, this unconnected elaboration of thought is called discursive prose.

Rhetorical traditions and academic disciplines, on the other hand, are all about the progressive development of a conception, the methodical construction of a logical connection between one thought and the next in a type of writing called expository. Expository prose explains things; it begins somewhere, ends somewhere, and has a reason for going there. If in discursive prose thoughts are sticky, catching any idea in the air around them, in expository prose they are cohesive, each being designed and suited for the next thought made to follow. Instructively, the adjectives cohesive and coherent are linguistically related.

Here is an example of discursive prose: I’m planning a trip to California this winter. I have a lot of projects to finish at home this summer. I am going to build a new patio, the old cement tiles there now have cracked over the years, expand my garden so that I can grow my own vegetables and save some money at the grocery store, and I have to generally fix things up around the house. I’ll need a well-deserved vacation. Notice the tone or manner of the passage: it has all the character of someone thinking aloud, someone thinking off the top of his head and following whatever idea next happens to arrive. The idea of the first sentence, planning a trip to California, is not addressed again until the last sentence of the passage. Between those two, there is a cluster of ideas which presumably have to do with the writer’s deserving a vacation (the predicate of the last sentence), but they do not cohere through structure, punctuation, or the arrangement of words. Just as often in casual conversation, we are left to find the connection to the thesis announced in the first sentence.

By contrast, here is an expository version of the same passage: I’m planning a trip to California this winter to give myself a well-deserved vacation. I will have finished a lot of projects at home this summer—replacing the old cement tiles on my patio, planting vegetables in the garden to save some money at the store, and caulking and painting some windows around the house. Observe first how more concise this passage is (trimmed by almost 25%, in fact), and notice too the more deliberately constructed sentence structure. The first sentence here combines the first and last of the discursive version, and the balance of the passage—one sentence—is more accurate in tense (note the future perfect will have finished), concisely specific in detail (combining the two clauses of the second sentence into one), and interesting in sentence design (parallel structure with an energetic dash to mark the examples of the projects to be finished).

Expository prose, then, is disciplined discursive prose. Discourse, which means conversation or talk, gives us the adjective discursive, and just like conversation, discursive prose often goes in all directions helter-skelter in an attempt to bring someone else into its orbit of ideas. And also like conversation, the term discursive can ambiguously mean either rambling talk or coherent comment. If we can remember though that coherence best serves our attempts to represent the ideas we have in mind, we can avoid then the censure of sticky thoughts and compose prose that is coherent and fitted to the task at hand.

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Well, that depends. And what it depends upon can help us both to review a point of grammar and to sharpen our critical thinking.

We use words to represent our mentality, our state of mind, about a given circumstance. We might be in the very situation about which we are constructing sentences, or we might be depicting a moment in the past or projecting one into the future, real or imagined. No matter how precise we try to be in our choice of words and arrangement of grammatical elements, however, the truth of the matter is that language is often a rough-hewn attempt to bring a circumstance before the mind of another to consider. One word may mean many things, and we may regard this uncertainty either optimistically as a rich ambiguity, or pessimistically as a hopeless chaos. Let’s go with the former.

In this sentence, for example, what does the verb feel mean: After hearing their side of the story, do you feel different about it now? In analyzing a verb, it is practically very helpful to remember the three classes by which they are categorized: transitive, intransitive, and copulative. A transitive verb always works together with a direct object (I felt the warm sun on my arm); an intransitive verb does not work with a direct object, but represents instead the action itself alone (the blind man felt for the door); and a copulative, or linking, verb identifies the subject with some thing or some quality (she felt cold). We can recognize a copulative verb more readily if we can see that the verb to be is assumed (logically, not stylistically) somewhere in the predicate: she felt herself to be cold.

With that quick review, let’s look again at the sentence: After hearing their side of the story, do you feel different about it now? Does the subject you feel anything directly? There is no direct object, so we cannot classify the verb feel as it is used here as a transitive verb. We can, however, understand that feel in this context means to be conscious of something, to be aware of a quality of difference, or dissimilarity in oneself. The verb feel, therefore, functions in this particular sentence as a copulative verb, and the adjective different names the quality with which the subject you may be identifying itself. The adjective different, in other words, describes the subject you, as it would, for example, in saying I feel sad about it.

But if we now change the adjective different to the adverb differently, how does this alter the meaning of the verb feel: After hearing their side of the story, do you feel differently about it now? Adverbs modify verbs, not nouns or pronouns, so with this change, the writer or speaker has altered the angle of meaning, so to speak, along which we as readers or listeners are to perceive the emphasis, the significant concern, of the statement. Since the adverb differently can only refer to the verb feel, that changes the status of the verb from copulative to intransitive, because there is no longer an adjective in the predicate. That is to say, the question do you feel no longer means what quality are you conscious of being in your own mind, but do you think in a different way about the situation. To feel meaning to think is now an intransitive verb, which must be modified appropriately by the adverb differently, not by the predicate adjective different.

The answer, then, is that both statements are correct, depending upon what one intends to say. As readers and listeners, we must discern the situation and look to other words in the sentence for cues and clues. The prepositional phrase about it, for example, might suggest the copulative interpretation, because to feel about often expects an emotional answer. But that would not be conclusive evidence, and so absent a larger context, we must respect the ambiguity and look closely at what conclusion the grammar supports.

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What is the difference between a paragraph and a stanza? Or, put another way, what is the difference between prose and poetry? Prose (the word comes from the Latin phrase prosa oratio, straightforward speech) is the sentences our everyday mind produces, saying this about that, constructing thoughts in clauses, and linking one after the next, paragraph by paragraph, into a concatenation of meaning. Interestingly, we also call this kind of language discourse, a word again from the Latin meaning to run about here and there, a linguistic phenomenon we see daily indeed.

Poetry, on the other hand, has less to do with constructed rational thought than language attempting to evoke an immediate awareness. Where prose is elaborate and extensive, poetry, we might say, is pulsive; where prose wants connection, poetry wishes for immediacy; one is horizontal, the other hierarchical or within the objective world prose assumes. Prose makes a world of things in order to find meaning through the joining of one thing with another. Poetry wants a world where things stand beside one another, the mere presence of one thing affecting the presence of another. These two ways of knowing, however, are complementary, not competitive, and in excellent work of either prose or poetry, it should be possible to find one way informing the other.

Here is a line from William Wordsworth, a poet of undoubted reputation and insight. He speaks, of course, from nineteenth-century England, a time and place different in temperament and idiom than our own, but similar too, perhaps one could say even identical, when it is a matter of discerning universal value. His poem “It is a Beauteous Evening, Calm and Free” opens with these arresting lines: It is a beauteous evening, calm and free, / The holy time is quiet as a Nun / Breathless with adoration; the broad sun / Is sinking down in its tranquility. If we approach these words with our everyday discursive mentality, as indeed we must always when we begin to read, we can quickly understand what the lines depict: a quiet evening at sunset. With our rational understanding of the structure of the language, we recognize a simple independent clause in the first line, another in the second line, no verb at all in the third, and a predicate in the fourth. All that our critical eye ascertains, and so it must, consciously or not, in order for us to take meaning from the words.

But if a prosaic depiction is all we understand, then we might well be missing a further meaning, richer and more poetical, which that same analytical understanding of the grammar can help us see. Always there are the adjectives to consider: we know what it means for an evening to be calm, but what are we to think of a free evening in the opening line? Beauteous there in the first line is an adjective almost restricted now to poetic diction, but a holy time we recognize more easily, as we do a quiet nun. In that same second line, though, there is also the conjunction as, and if we pause a moment to think about what logical effect that simple conjunction has on the meaning of the line, we will discover that this little word creates an ambiguity which, if we do not miss it, will make the poetry a richer experience for us than what it merely meant on a first reading.

Our grammar will tell us that the word as is a subordinating conjunction. As a part of speech, conjunctions are the logical switches in a sentence, telling the reader how to relate one idea to another logically. Very many conjunctions have more than one such logical function, and among the many uses of the conjunction as are the distinct ideas of comparison and manner. At first sight, we probably understand the second line of Wordworth’s poem to mean the holy time is as quiet as a nun; we could assume, justifiably, that the first as has been omitted by ellipsis (as we might say, he’s rich as a king), and so we likely understand the assertion to be a simple comparison between the quietness of the evening and the quite solitude of a nun. But the conjunction as may also render the meaning of manner, or illustration (as when we say, he comforted me as a brother), in which case we could interpret Wordsworth’s second line to mean the time is quiet, as a nun is quiet. Here, the noun nun represents not another entity to be compared to the quiet evening as sharing the quality of quietness, but something—someone—who possesses in and of herself the very essence of the tranquility, giving us the chance to see the same quality fully itself in two very different worlds, nature and divine devotion. Indeed, Wordsworth goes on in the very next line to extend the illustration by pointing to the effect such devotion has on the nun, who is breathless with adoration, a wonderfully beautiful phrase to evoke—not assert—the same passion one might have for the quiet, resting evening in the first world.

We begin reading a poem by understanding its elemental grammar, and we do that with our everyday rational mind with its prose habits of thinking. But a poem is there before us to brighten our awareness of something in our common world as the poet sees it, not to explain it prosaically to our rational frame of mind, but to present it anew for us to know more profoundly. The poetic insight must rest on rational form, but unless we sometimes loosen the words from their obvious first interpretation, we might not arrive at the deeper vision the poet wishes to show.

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