There are two corrects ways to utilize a semicolon, the first being the most common. Linking two complete sentences together, the semicolon acts as a period, but unlike the period, which can unite any two complete sentences, there should be a strong correlation between the two sentences for the semicolon to be used correctly. Look at the two examples:
Bad use of a semicolon: Our world is a place of considerable suffering; the platypus skate blissfully across the lily pads.
Notice that while both examples contain complete sentences, the second example is an incorrect use of a semicolon because the two sentences have little relation to one another (or do they?).
The second correct way to utilize a semicolon is far less common, but should be on your radar. You probably learned in grade school that when you have a list of three or more things, you should have commas separating each object. However, what about a situation where you have a list inside a list? Whatever will you do? Thankfully, like Han Solo swooping in last minute to save the day, the semicolon functions as the loveable antihero, separating the primary elements of the list while commas separate the secondary elements. Look at this example:
The platypus is a hodgepodge of animal essences. It has the body and tail of a beaver; the feet, bill, and egg-laying potential of a duck; and the venom of a mildly toxic snake.
When the platypus is angry; the world trembles.
In this example, we do not have two complete sentences, so a semicolon is not necessary. Instead, a weaker comma would do the trick. The second common incorrect use of a semicolon is when utilizing it with a conjunction like the example here:
I fear no creature walking this Earth; but the platypus is not of this world.
Once more, a simple comma will fit the bill. In this final example, many students will use the semicolon to introduce quotes or lists, but this is a job for colon. Look at this incorrect example:
As George Washington once said; “If the British had an army of platypi, our defeat would have been certain.”
Use the colon to introduce lists, phrases, and quotations. Use the semicolon to link sentences with a strong relation. Use chicken eggs for breakfast omelets. Use platypus eggs in pagan rituals.