Discussion Groups / English Usage / January 2010

That's incorrect, because two sentences have been linked by a comma.

That's not a bad example for a colon. The colon tells the reader that there
is a logical link between the sections before and after it. In your
particular case the colon says "I've just told you technology doesn't exist
in a social vacuum, and if you stick with me I'm going to explain that,
conversely, it is embodied...". So you will find a colon if the sense
demands "rather" or "instead" or something like that.

A similar use will be found if you imagine "namely" after the colon. For
example, I've just told you something about colons: that they're quite
useful if properly used.

I don't like this, because the "and" is illogical. "But" would be more
logical if you were going to express the sentence in that manner.

Regards

Jonathan

If true, this worry seems unnecessary.   Many people write
English just as they wish without using colons or semicolons;
when readers encounter them, their function in the sentence
is usually obvious.

A semicolon replaces a conjunction in linking two clauses; a colon
ends a sentence and promises that there is something to follow: an
example, a list of things, an explanation, etc.

"Masa" asks about:

It is common in informal usage to use a comma this way, especially when
the sentence is very short.  "I never do, it's too hot."

The colon is correct, but I think I would use a semicolon.  Certainly
it's correct either way.

The semi-colon is used when we want a weightier separation of ideas than
the comma provides, but less of a one than a period (making two
sentences) would make:

 1. John likes these sorts of affairs; Mary doesn't.

Now that could be rendered in at least two other ways :

 2. John likes these sorts of affairs, but Mary doesn't.
 3. John likes these sorts of affairs.  Mary doesn't.

None of the three is wrong, and none especially correct: it is a matter
of what the writer wants the reader to feel.  In #3, the break is quite
heavy: it produces a tone of sharpness, terseness, bleakness.  It might
fit well into a sort of hard-boiled-dick tale.  In #2, we have a sense of
babbling, of something that is not in sheer grammatical terms a run-on
sentence, but that sounds like an old lady who has started talking and
can't stop.

The colon is used to introduce a statement that expands on or explains
what went before it: in essence, it is the delivery of goods invoiced in
the first part of the sentence.  I have used it in that way several times
in this post.

Note, incidentally, that a colon does not end a sentence any more than a
semi-colon does: what follows is still part of the same sentence.  That
remains so even when, for clarity, the rest of the sentence is broken out
as a list, perhaps even a list with bullets or numbering, and thus such
lists should be accordingly punctuated.

For example, I might list the marks we are discussing:

  . the comma;
  . the semi-colon;
  . the colon; and
  . the period.

Note that despite the indenting and bulleting (which could as well be
numbering), we still insert punctuation.

That last also incidentally shows another use of the semi-colon: it can  
replace the comma in serial listings, and is especially useful in thta
capacity when the elements of the listing are each complex (and
especially if they contain commas).

  I like ham and eggs; bacon; grilled-cheese sandwiches; and peanut
  butter and jelly sandwiches.

  The various flags were of many colors: red and green; white and blue;
  red, yellow, and green; and the good old red, white, and blue.