Here, indeed, it may be that the second and third sentences are halves of one idea, divided to make its parts more emphatic. At all events, while a sentence may be very short and still constitute a principal factor of the paragraph, sentences should not be so brief that each is, so to speak, only half a main thought. A main thought may be composite. Thus, it is often effective (a) to state and to explain an idea very briefly, within the one sentence; (b) to show an extremely close relation of cause and effect, by stating both within the one sentence; (c) to contrast two things very briefly within the one sentence.
Now, a child gives his ideas in mere bits; he cannot express the relations of the bits to each other. For example:—
My aunt was a very large woman. My uncle was a very thin man. He was very delicate. He dwindled. I mean, he got thinner and punier every day. And my aunt thought a great deal of him. She wished him to get well. She gave him a great deal of medicine. She gave him so much that he began to get worse. He finally died.
This paragraph tells the story of how a woman doctored her husband to death. The writer has made eight steps in the story, which perhaps has not really more than four main parts: (1) The contrast between my aunt and uncle. (2) My uncle “dwindled”—explained by saying he got punier daily. (3) My aunt’s love, and its consequence—her wish for my uncle’s recovery. (4) The form the wish took,—giving of medicine. (5) The twofold result,—aggravation of the disease, then death.
The original sentences may be combined into four. In combining them, what pointing shall be used instead of so many full stops? We may use commas, but only if we make one clause dependent or join two clauses or propositions by a conjunction. We may say, for example, “My aunt was a very large woman, and my uncle a very thin, delicate man.” We have inserted an and; this permits the use of a comma. The result is a pretty good sentence, having one complex idea,—the contrast between the ample lady and her slight husband.
But another invaluable means of showing the real factors of the sentence is the semicolon. The semicolon, as was said in Chapter [III.], is a kind of weak full stop. Nearly always it connects statements that are unrelated and independent grammatically, but intimately related in sense. In a way,[19] the semicolon connects sentences, a period separates sentences. The former sign is priceless to the writer who, when he comes to expand each idea of his paragraph, finds the structure growing too complicated. He has merely to place a semicolon and go ahead with a miniature new sentence, which every reader will understand to be a part of the logical unit in hand.
If we combine the eight sentences by the help of the semicolon, we get four, somewhat like the following:—
My aunt was a very large woman; my uncle, on the contrary, was a very thin delicate man. He dwindled; that is, he got thinner and punier every day. My aunt thought a good deal of him, and naturally she wished him to get well. She gave him, accordingly, a great deal of medicine. She gave him so much indeed that he began to get worse; and, finally, he died.
Most students do not use the semicolon enough. Two or three semicolon clauses, however, are sufficient for a very long sentence. If more are written there is usually danger of encroaching upon the next main thought of the paragraph. It is better to write too many short sentences than too many long ones.