Please can someone teach me about use of colons and semi colons?

[Bumperslucious]

I do lots of report writing at work and a colleague who proof reads my reports often puts colons and semi colons in. Despite being pretty well educated (I had to add that in there, I'm not stupid) my understanding of how to use these punctuation marks is woefully lacking. Can anyone give me any tips/rules of thumb? I feel it might be intrinsically linked with comma usage, of which according to my colleague is not great either.

Hiya, hope this might be of some help though probably quite simplified but works OK for me.

Colon Introduces a list or quoted direct speech
Semi colon Separates 2 complete sentences which are closely interrelated and interdependent in meaning. Can also be used to separate items in a list that are longer items and are separate sentences themselves.

My copy of Fowlers says:
"The four stops (,)(;)(: )(.) form a series, each member of which directs us to pause for so many units of time before proceeding. There is essentially nothing but a quantitative time relation between them."

Translation: if you are having a quick breather, use a comma; if you get to the end of a thought process / sentence, use a full stop. If you are somewhere between these extemities use semi or full colons.

senua is right I would say, but can I add a rider.

Don't use semi colons or colons if you are not sure.

Within most sentences, a comma is a sufficient pause.

A colon yes needed for introducing something eg speech - she said: "Is this right?" but otherwise not often.

semi colon maybe in a list eg He picked up the dog that her mother had bought; bought the newspaper that his friend had asked for; and ordered the cup of coffee that his brother wanted. But even then (what a ludicrous sentence anyway) I think commas would be fine.

I suspect your colleague is just showing off his own lack of knowledge by using what he doesn't understand, bumper

I was told that two independent sentences without a coordinating conjunction/marker absolutely need a semi-colon, not a comma, or you have a comma splice. Is that wrong? Or is it specifically US grammar?

Here's the link I was given.

I struggle a lot with grammar. I was never taught any at school, so everything I know comes from reading, or adult correction.

So, simply, is it something like this?

I went to the shop; I had to buy something for tea.

I'm always tempted to put a dash in that sort of sentence.

Me too. In all honesty I think it's quite specialised knowledge. The US seems a lot hotter on pernickety grammar in schools, and I was corrected on comma splices by a US friend (she wasn't being snide; she knows I like to be told if there's a glaring error). I thought semi colons were just for lists and to add emphasis, before. Perhaps they are in this country? I just don't know, so please don't just take my word for it. As I say, my formal knowledge of grammar is quite limited.

Funnily enough, they're not taught that commas are stylistic pauses at all in the States, as far as I can work out. I've been told that they were strictly instructed never to use one unless grammatically imperative, and I've read as much in a book by Lionel Shriver. (A character sneers at his college students for gratuitous comma use.) Here, that's all I ever was taught.

Wikipedia is surprisingly helpful on the subject, actually.

Read this here
simply put I think.

I was being selective with my quotation from Fowler. He goes on for pages about stops! He discusses the use of commas for reasons of style, which he calls rhetoric, as mentioned by Qally. He gives an example thus:

The master beat the scholar with a strap.
The master beat the scholar, with a strap.

The introduction of the comma does not change the logic of the sentence but does change the emphasis and highlights the instrument that the master is using to beat the scholar.

See, the second sounds better, in my opinion. It just does. But I know that some US teachers would tell their students that was gratuitous/misplaced.

Personally, I think there's a danger in grammar becoming a straitjacket instead of a tool. It's a shame, if all people see is a rigid structure, and they lose sight of the rhythms and cadences and intonations of language. It's reductive, if that isn't too pretentious.