Colons cause problems. In 101 English Tips, I wrote:
a) a colon “shouts out that an example or summary is about to follow.”
b) “Another colon tip: when continuing to write after a colon in your sentence, it is often a reasonable and admirable idea to make it snappy and not produce a sentence that looks like a little poodle with a long, long tail. Oops.”
The only punctuation following a colon will generally be a period or question mark or exclamation mark (and commas, of course). Do not start a new clause.
This is bizarre:
Ogden Nash writes of a hunter: ‘This grown up man with pluck and luck / Is trying to outwit a Duck,’ AND THIS shows…
Write this instead:
Ogden Nash writes of a hunter: ‘This grown up man with pluck and luck / Is trying to outwit a Duck.’ THIS SHOWS…
Also, never, ever use two colons in a single sentence. A colon and dash in a single sentence? Nope.
A final point: one-third of the mistakes students make are explicitly covered in 101 English Tips, however, they persist (this sentence- five or six).
All Language Notes of the Week are available at:
http://www2.arnes.si/~bjason/LNW.pdf