Much like others, I can, at times, bandy around words and only have a vague idea of what they actually mean to me and of what they mean to others. I can be so busy building ideas that I don’t step back enough sometimes to look carefully enough at the words I’m using, the building blocks, and think carefully about their definition in my mind and their meaning to others. I am reminded here of something the novelist Joseph Conrad said in a letter to Robert Cunningham Graham. He said rather bleakly, as was his wont: “Half the words we use have no meaning whatever and, of the other half, each man understands each word after the fashion of his own folly and conceit. Faith is a myth, and beliefs shift like mists on the shore; thoughts vanish; words, once pronounced, die; and the memory of yesterday is as shadowy as the hope of tomorrow”. But I do generally try and deal with that scenario (well, at least some of it!) and I will try to do so here and, first, by looking at what we actually mean by the linguistic term sentence.
What is a sentence? Or, to put it another way, what makes a sentence a sentence? Quite simply, at least in English, a sentence is a collection of words that has a subject and a verb. If a collection of words does not have a subject and a verb, it can’t, in English at least, be a sentence. English is extremely clear and robust on this. (Well, no, not quite – a command sentence does not have a subject but, as an imperative verb cannot have a subject [as in Stay longer], it is accepted as a sentence without a subject.) A sentence can have other functional types within it in addition to subjects, objects and verbs, but it does not need them in order to achieve the status of a sentence. So, for example, we can say (rather unveganly):
I like cheese.
We have here a subject (I) and a verb (like) and an object (cheese). We have, here, a sentence and we confirm this orthographically, by starting with a capital letter and ending with a full stop. “Ah,” but you might say, “well, you can’t say ‘I like’ as that is not grammatically correct, but you are saying that that would be a sentence as that would have a subject and a verb.” I would counter that the synthetic grammar of the verb like demands an object (conventionally, the verb is transitive) because the synthetic grammar is semantically sensible in that we can’t just like at random and, in general, we need to have something/someone to like. The general synthetic grammar, on the other hand, doesn’t demand an object as shown in this interchange:
A: Who likes cheese?
B: I do.
Here, B’s reply to A is a sentence and is orthographically treated as such, because it has a subject (I) and a verb (do) – the notions of ‘liking’ and ‘cheese’ have been ‘sandwiched’ into do semantically. And, there are many verbs that don’t require an object (intransitive verbs), with which we can have a sentence where there is no object, but just a subject and a verb, as in:
A: Where’s Tom?
B: He is sleeping.
In He is sleeping, we have a subject (He) and a verb (is sleeping). Sleeping does not require an object. In a sense, sleeping is its own object (‘he is sleeping a sleep’); it does not need a separate object. Everything is ‘hunky-dory’ with the synthetic grammar (in terms of synthetic potentials and constraints) of He and of is sleeping and there is perfect sense and we have a sentence, just of subject and object.
Overstretching the notion of a sentence
A sentence in English does not readily accept two subjects in the same sentence. Once a subject and a verb have got set up in their own sentence, the subject is quite proprietorial about what they’ll let into their sentence – they don’t want a separate variant of themselves in the same sentence, as in:
Mary likes cheese Tom doesn’t like octopuses.
English says ‘No, no, this is all getting a bit too random’. It says that this is not a sentence but two sentences and wants that shown orthographically, thus:
Mary likes cheese. Tom doesn’t like octopuses.
Mary likes cheese; Tom doesn’t like octopuses.
However, English does operate with a little discretion in this area; if the two sentences are closely related in meaning, or even a bit list-like, it can accept a comma in this kind of instance. The comma indicates an acceptance that there is a division between the two collections of words but it does not insist that they are entirely separate sentences:
Mary likes cheese, Tom likes ham.
In terms of over-reducing the notion of a sentence in English, we can posit that English does not really need there to be a subject for a sentence to be a sentence and that, maybe, there just needs to be a verb. We could suggest that Is raining is perfectly sensible as a sentence – after all, you can say in Italian Piove (literally ‘Rains’) to convey, in a sentence, the idea of ‘It is raining’. So, why not in English just say Is raining, where the verb rain is understood to have its own implicit subject of ‘rain’, just as He is sleeping has its own implicit object of ‘sleep’? But, English is a bit inflexible on this in that, however seemingly illogical it is to have a subject, there has to be one, at least grammatically, though not semantically. English stands firm on this – Is raining is not a sentence, but this is:
It is raining.
Interestingly, Italian takes a different position on the definition of what makes a sentence a sentence from English, in that it does not insist on a setence having a subject, as in:
Piove. (literally ‘Rains’ = ‘It is raining’)
L’ho già visto. (literally ‘Him/Her/It (I) have already seen’ = ‘I have already seen him’)
L’ha già visto. ( literally ‘Him/Her/It (he/she/it) has already seen’ = ‘He/She/It has already seen him/her/it’)
Italian takes a different position on what makes a sentence a sentence, but it shows that it is a sentence in its terms in the same way with an opening capital letter and a closing full stop.
So, in short, a sentence is what a language sees as a grammatically complete functional structure, with an acceptable number (not too many, nor too few) of each type of functional element (subject, verb, object, etc).