The colon ( : ) is most regularly used to start a list of some sort.
- We bought quite a few things for the party: balloons, drinks, cakes and biscuits.
- There were representatives from three countries: Canada, Mexico and Bolivia.
This is by far the most common use of the colon.
We can also use a colon to introduce a quotation.
- The judge put things very succinctly: ‘Criminals will be punished.’
More traditionally the colon was used to introduce an explanation or additional information.
- The stage was set: now we just had to carry through our plan.
- There was one difficult remaining task: he had to talk to his father.
In some instances you will now find that the colon in such sentences has been replaced by a semi-colon, or even by a dash.
- The breakdown of her marriage had affected her deeply; she would bear the scars.
- The weather conditions were appalling – he didn’t know how long he could hold out.
As suggested in the sentence above, the semi-colon is a punctuation mark that lies half way between a comma and a full stop. In some ways it resembles a strong comma or a weak full-stop. It is often found linking two clauses (groups of words that could stand alone as sentences) in preference to a full stop. We often use it where the two clauses are very closely linked and we want to emphasise that connection. We may also use it if one of the clauses is very short and wouldn’t easily stand alone.
- He was furious and vowed revenge; I knew he would do nothing.
- The garden looked wonderful; the grass looked like silk.
- I wanted him to make a gesture of support; he refused.
Certain words very frequently follow a semi-colon and the most common one is however.
- She was very aggressive; however, I refused to be bowed.
- Trade often benefits both parties; however, this is not always the case.
Other words that follow the same pattern are: nevertheless, moreover, hence.
- I was absolutely exhausted; nevertheless, I battled on.
- He had little money in the bank; moreover, he had a poor credit rating.
- He had been bitten as a child; hence his fear of snakes.
Note that hence is the only one that does not need a following comma.
We also use the semi-colon in lists which involve phrases and may be rather complicated. The semi-colon helps to make them clearer. Note how the list starts with a colon.
- I wanted so many things for the house: a new washing machine; an effective vacuum cleaner; an economical dish-washer; a fast computer as well as a computer table.
- I went to France and Spain in 2005; Italy, Greece and Croatia in 2007; and Cuba, Argentina and Chile in 2008.