An independent clause is a clause that can stand alone as a sentence, often expressing a complete thought. For example, ‘I like chocolate biscuits’.
We can join independent clauses together to combine ideas. This could be done by using a conjunction (a word used to join clauses in a sentence together to make multi-clause sentences). For example, ‘I like chocolate biscuits, but I couldn’t eat a whole pack’.
Where two or more independent clauses are used in the same sentence, the boundary between them can also be marked with a semi-colon, colon, or dash.
A semi-colon is used used between two independent clauses that balance each other and the writer feels that they are too closely linked to be made into separate sentences. For example:
‘I’ll be there on time tomorrow; that’s a promise.’
A colon is used between two independent clauses where the second clause follows from the first, perhaps explaining or qualifying it further:
‘All the practice was worth it: the boy got full marks.’
A dash can be used in the place of either colons or semi-colons:
‘I’ll be there on time tomorrow – that’s a promise.’
‘All the practice was worth it – Tom got full marks.’
Dashes tend to be used more in informal writing.