How should I use a semicolon?

There are several ways to employ a semicolon but let's focus on just one. Semicolons are most commonly used to link two clauses together, e.g. Gregory ate all of the cheese; his sister was not impressed. To understand semicolons, then, we really just need to understand clauses. A Clause is basically a phrase that contains both a verb (an action word) and a person or thing who is doing the verb. Any grammar fans out there will know that this is sometimes called the subject.For instance, in the example above, 'Gregory ate all of the cheese' is a clause because it contains a verb ('ate') and a person who is doing the verb (Gregory). Though it might seem less straightforward, 'his sister was not impressed' is also a clause, since it too contains a verb (was) and a subject (she). In contrast, 'eating all the cheese' is not a clause. 'Eating' has a verb, yes, but we don't know who is doing the eating as there is no subject. Because they contain a verb and a subject, clauses can stand alone as sentences. The example above could alternatively be written as: Gregory ate all of the cheese. His sister was not impressed. By joining the two together, though, we begin to move towards a smoother, more elegant type of writing. The use of the semi colon highlights that the two clauses are linked, that Gregory’s sister is unimpressed precisely because Gregory has eaten all the cheese.