Using semicolons is essential for English courses, the SAT grammar section, and writing application essays to prep school and university.

Like a Soft Period Saying “Wait! There’s More.”

The semicolon can be replaced by a period. This means that it separates two separate sentences that could “stand on their own”. Here is a good usage of a semicolon:

My cat and I are bonded for life; I raised her since she was a kitten.

Both parts of the quote are separate sentences that could stand on their own. In other words, the semicolon could be replaced with a period and still make sense:

“My cat and I are bonded for life. I raised her since she was a kitten.”

Here is now a wrong usage of a semicolon:

I really love cats; their independence, speed and hunting skills.”

This a bad usage of a semicolon because the semicolon could not be replaced with a period. If it were, the second part of the quote would be an incomplete sentence:

I really love cats. Their independence, speed and hunting skills.

This, on the other hand, is a good usage of a semicolon:

I really love cats; their independence, speed and hunting skills always amaze me.”

Notice that in the above quote, both sides of the semicolon are full sentences on their own, and the semicolon would be replaced with a period:

I really love cats. Their independence, speed and hunting skills always amaze me.”

Since a semicolon is just like a period, you might be wondering when or why we would ever use one. We could, in theory, just use periods. However, a semicolon, despite syntactically working just like a period, is a little bit “softer”.

When I read through a period out loud, I really pause my speech. There is a silent moment or beat that happens in a conversation. On the other hand, when I read through a semicolon, my pause is shorter — it’s almost like I’m raising my finger in the air to silently say “but hold on, there’s more”. This tells the reader or listener that more essential information or context is coming in the next sentence.

I ended my dog’s life; he was 22 years old, extremely ill, and it was time to stop his suffering.

The semicolon above could be replaced with a period, since “I ended by dog’s life” is a sentence, and so is “He was 22 years old, extremely ill, and it was time to stop his suffering.” However, a period in that sentence would force the reader to “hard-pause” after the first sentence. The reader would say “I ended my dog’s life.” Then the reader would pause for a second. This would be quite a shocking thing to say, and is missing context. You would want to quickly get to the second part of the sentence, which explains that the dog was sick and suffering. The semicolon here is silently saying “but wait, there’s more,” which lets the reader know that the second portion of the sentence will help contextualize the first part.

Semicolons for Complex Lists

There is a rarely used case for semi-colons that happens a few times on the SAT writing section. It is used to help write complex lists.

Normally, when you write a list, the items in the list are separated by commas.

Lauren loves animals, plants, vegetables, and fidget toys.

In the sentence above, we had a list of four items. They were separated by commas. Sometimes, lists get more complex, like this:

Lauren loves animals that are independent, plants of the monstera family, pickled vegetables, and expensive fidget toys.

In this list, we were still able to separate our four items with commas, but each of the items had a tiny description of its own. I can make some of these list items more complicated by describing them in further details: let’s change “plants of the monstera family” to “plants of the monstera family, specifically the variegated ones that have white patches”. Let’s also say I want to change “pickled vegetables” to “pickled vegetables, like cauliflower or anything crunchy.” Let’s try to adjust our list with those new items.

Lauren loves animals that are independent, plants of the monstera family, specifically the variegated ones that have white patches, pickled vegetables, like cauliflower or anything crunchy, and expensive fidget toys.

Notice how the comma between the words “family” and “specifically” is not separating two main items. Rather, it is being used in a description of one of the items (the plants). The comma between “vegetables” and “like” is also not separating two main items; it’s being used to give details about an item (pickled vegetables). In this horrendous sentence, some commas are being used to separate main items, while other commas are being used as “mini commas” to give details about the list items. When this happens — when you find yourself needing “big commas” and “little commas”, you need an extra syntactical tool to help you split up the main items in a clearer way. This is where the rare case of the semicolon comes in — the semicolon can sometimes be a used a “big comma” that separates the main list items. In this case, the rules about it being replaceable with a period is not applicable here.

Lauren loves animals that are independent; plants of the monstera family, specifically the variegated ones that have white patches; pickled vegetables, like cauliflower or anything crunchy; and expensive fidget toys.

Notice how each element in the list has commas within it, but the main items in the list are being separated by the “super commas” (semicolons).