When we begin to look more closely at the sentences we read and write, it can often be more difficult than we might think to identify the subject of a statement. A first course in grammar will explain that the subject is what the sentence is about, but that can be confusing because more often than not, a sentence is talking about a lot of things. The sentence Chicago has many beautiful parks along Lake Michigan has three nouns, Chicago, parks, and Lake Michigan, so we might well ask which of those three things this sentence is about.
Here’s where a little higher approach to grammatical analysis might just be more practical. Traditional grammar understands words to be symbols for ideas. The word idea derives from a Greek verb meaning to see, and so an idea is something we see, an image or picture that has been produced in our mind by something we’ve perceived, either in the so-called real world or in the interior region of our mind itself. A sentence like Chicago has many beautiful parks along Lake Michigan actually contains (at a minimum) the three ideas represented by the three nouns. Recognizing that, we can ask a better question to find the subject of a sentence: what is the idea about which something is being said? That means that the subject of a sentence must be working with a verb, because a verb is the word that makes an assertion, or what is called a predication, of some kind.
So the sentence Chicago has many beautiful parks along Lake Michigan is not really about parks, although parks are involved with what the sentence is really concerned to assert: nothing is being said about the parks. Nor is the sentence about Lake Michigan, although that idea, that mental picture, is also involved in the predication; for what would the writer answer to our direct question, what are you saying about Lake Michigan? He could only answer, I’m not saying anything about Lake Michigan; I’m talking about Chicago. And right there would be the heart of the observation that is important to us as critical readers: a subject must have a predicate, and a predicate is made up of a verb. And so the two questions that are of fundamental importance in rational discourse—a fancy phrase for reasonable conversation—are: what are you talking about? and what are you saying about it?
So why all this? Because we good humans are impressionable creatures. The grammatically simple sentence Chicago has many beautiful parks along Lake Michigan is not so simple logically, as is not this grammatically simple sentence: With infection rates rising dramatically in a number of states, the question whether to get vaccinated looms over every person. This sentence is not in fact asserting that people should get vaccinated, although we might think that it is implying that. The subject of the statement is the question whether to get vaccinated, because that is what looms over every person: there is the subject and predicate combination, the central assertion and the ultimate reason why the sentence was composed and said. But there are also other ideas present: infection rates and states (to say nothing of a higher order of ideas, including rising and the idea of multiplicity in the phrase a number of). But where is the verb for infection rates? Rising is not a verb; it is a participle, which is an adjective built from a verb. Adjectives imply, they don’t assert. And where is the verb for states? That idea is part of a prepositional phrase, and phrases, like participles, do not predicate anything; they only assist in the assertion a verb is making elsewhere in the sentence.
There is, then, a material difference between asserting and implying, and good writers (whatever the quality of their character) can do a lot to influence what we think by manipulating sentence structure. And that is why the schoolmarmish question of where’s the subject is really of quite some importance. For if I believe that every idea in a sentence is of equal importance just because it’s been mentioned, then I run the risk of living in a bipolar world of black or white and right or wrong. And that, indeed, is a dangerous place to live. We think in and with our language, and the more familiar we can become with how it works, the more aware can we be of the complexity of simple-appearing ideas.