Brief notes in a series on the grammar and rhetoric of punctuation
The first consideration of punctuation is grammar: the mark must fall within the scope allotted to it grammatically. But the second is rhetoric. To punctuate beyond mere correctness, to punctuate with verve and flair, to punctuate so as to more clearly elucidate meaning, you must consider rhetoric.
Periods — come between two ICs (unless fragments are being used for effect)
Represent the strongest break between two thoughts, bringing the reader to a full halt.
Semicolons — come between two or more ICs (unless used as a “strong comma” between internal phrases or clauses)
■ Represent a softer break than a period: semicolons often signal a balanced thought (two like thoughts to be compared or contrasted).
■ Two thoughts linked by a semicolon have a special relationship: the two are to be taken and weighed together.
■ You can often imaginatively replace the semicolon with “and,” “but,” “while,” or “instead.”
The tobacco companies produce products that kill the body; the networks spew out garbage that corrupts the mind.
People today don’t talk about their consciences and how to appease them; they talk about their guilt trips and how to avoid them.
English was the shoddy and ill-regarded language of hearth and home; Latin the language of prestige, of commerce, of scholarly discourse.
IC: clause (D or I).
Colons — preceded by an IC; followed by word, phrase, or clause (unless used to introduce a list)
■ Represent a softer break than a period: colons signal a thought carried further (the second thought in some way further explains, clarifies, or amplifies the first).
■ Two thoughts linked by a colon have a special relationship: the second makes clear the ﬁrst.
■ You can often imaginatively replace the colon with “because,” “that is,” “namely,” or “furthermore.”
Few people will admit to being superstitious: it implies naivete or ignorance.
This policy has introduced a new concept into German production: “birth to death” responsibility for commodities on the part of German manufacturers.
Unfortunately these “rules” are often taught as bona fide features of good writing: for many people the training wheels are never removed.
When punctuation alone shades meaning
Sometimes you’ll have a choice — grammatically and rhetorically — between breaking two thoughts with a period or a semicolon, or even with a period, a semicolon, or a colon. The mark of punctuation you choose affects the tone and import of the sentences.
They’re out to do clever tricks in the lab. They’re out to win awards and make money.
They’re out to do clever tricks in the lab; they’re out to win awards and make money.
They’re out to do clever tricks in the lab: they’re out to win awards and make money.
From a class taught through UCSC Extension in the mid-’90s through the mid 2000s