Colons and semi-colons
1 Colon (:)
A colon joins two independent clauses and draws the reader’s attention to the second clauses. It indicates something to follow, and by building a momentary sense of anticipation, it can thus add a certain kind of emphasis to the clause. It can also introduce a definition, a list, or indicate a logical conclusion, result or effect. It is also used in more formal letter greetings.
| Example | Type |
|---|---|
| There is something that graduate students simply cannot live without: coffee. | continuation, anticipatory, emphatic |
| President H. W. Bush spoke on the economy during his term: “In terms of the economy, look, I inherited a recession, I am ending on a recession." | continuation, anticipatory, emphatic |
| Floodwaters from the storm have closed the following sections of the city: the historical downtown district, the Garden Street district, the Happy Valley area, and sections along the highway. | list |
| Traffic light: a device that turns red as you approach it. | definition |
| There was only one possible conclusion: the ship had sunk. | conclusion |
| To Whom It May Concern: | letter salutation |
2 Semicolon (;)
2.1 As connectors
A semicolon can link two independent clauses with no conjunctions or connecting words, to imply a logical relationship between the two clauses. This creates a different flow than with two separate sentences. It often implies a logical connection such as sequence, comparison, cause, or result, in a more formal sounding manner, but using a semicolon instead of a conjunction or connector makes for a more formal, nuanced, implied, or understated relationship.
- The negotiators could not break their deadlock; they decided to reconvene and discuss the difficult issues after a one-week break.
- The mice brains were frozen and sliced into strips of 0.1 mm thickness; the slices were then examined for the effects of the drugs on neural tissues.
Semicolons can join two clauses with conjunctive adverbs (adverbial conjunctions) such as: however, moreover, therefore, consequently, otherwise, nevertheless, thus, furthermore. In all these examples, the first sentence could end with a full stop, that is, a period, but the semicolon makes the text flow more smoothly, creating a seemingly closer logical connection between both sentences.
- The negotiators could not break their deadlock; thus, they decided to reconvene and discuss the difficult issues after a one-week break.
- Drug X was not found to have any effects on neural tissue samples; however, Drug Y was found to increase dopamine levels, as expected.
- Gender was found to have a significant effect; therefore, it was entered as the first variable in the equation.
- We have increased server capacity to prevent overloads; furthermore, we have also upgraded our network switches.
2.2 For lists
Semicolons can also be used as “super commas” for sequences of longer phrases or clauses. This is especially common when the list is preceded by a colon, or a connector like i.e., e.g., for example, the following, or other similar markers of a coming list.
- We attempted to examine the following factors in our study: (1) how lexical subclasses of nouns affected usage of articles; (2) how semantic subclasses affected article usage; (3) recency effects and other contextual effects; and (4) individual style variations.
- For building our rocket, we need to parts and materials such as these: heavy metals to power the batteries such as uranium, plutonium or thorium; liquid fuels such as O2, kerosene or methane; and various metal casings.
