period

 (British, full stop). Two common errors are associated with the period, both of which arise from its absence. The first is the runon sentence - that is, the linking of two complete thoughts by a comma. It is never possible to say whether a run-on sentence is attributable to ignorance on the part of the writer or to whimsy on the part of the typesetter, but the error occurs frequently enough that ignorance must play a part. In each of the following I have indicated with a slash where one sentence should end and the next should begin: "Although GEC handled the initial contract, much of the equipment is American,/the computers and laser printers come from Hewlett Packard" (Guardian); "Confidence is growing that OPEC will resolve its crisis,/however the Treasury is drawing up contingency plans" (Times); "Funds received in this way go towards the cost of electricity and water supply,/industries, shops and communes pay higher rates" (Times).

 The second lapse arises when a writer tries to say too much in a single sentence, as here: "The measures would include plans to boost investment for self-financing in industry, coupled with schemes to promote investment and saving, alleviate youth unemployment, fight inflation, and lower budget deficits, as well as a new look at the controversial issue of reducing working hours" (Times). If the writer has not lost his readers, he has certainly lost himself. The last lumbering flourish ("as well as a new look.. .") is grammatically unconnected to what has gone before; it just hangs there. The sentence is crying out for a period - almost anywhere would do - to give the reader a chance to absorb the wealth of information being provided.

 Here is another in which the writer tells us everything but his phone number: "But after they had rejected once more the umpires’ proposals of $5,000 a man for the playoffs and $10,000 for the World Series on a three-year contract and the umpires had turned down a proposal of $3,000 for the playoffs and $7,000 for the World Series on a one-year contract, baseball leaders said the playoffs would begin today and they had umpires to man the games" (New York Times).

 There is no quota on periods. When an idea is complicated, break it up and present it in digestible chunks. One idea to a sentence is still the best advice that anyone has ever given on writing.