Sentence Unity

Before you start this lesson, you might want to review this basic lesson on sentences. I’m building on those basics here.

Sentence unity refers to several concepts: noun-pronoun agreement, subject-verb agreement, tense agreement, and using one idea per sentence.

It’s that last idea that we’ll look at here.

Multi-Idea Problems

In the lesson on sentences, I said that a sentence is a complete thought. Notice that “thought” is singular. Introducing multiple ideas into a sentence is a guaranteed method of confusing readers.

Identifying what counts as single or multiple ideas is an art, not a science. It’s also subjective.

I’ve got some tips below, but examining your sentences for possible confusion is the best way to improve your sentence unity.

The Good and Bad of Non-Restrictive Clauses

We know that non-restrictive clauses are non-essential, but not necessarily unimportant, ideas. Both of the following sentences contain non-restrictive clauses. Can you spot an important difference between them?

Example: My laptop, which is three-months-old, is broken.

Example: The office, which used to have a daycare and cafeteria, is located in the center of downtown.

We could rewrite the first sentence as: My laptop is broken. This sentence makes sense; it’s not essential to know that the laptop is three-months-old, but that information is relevant to the sentence (Three-month-old laptops aren’t usually broken).

So, in this sentence, the non-restrictive clause is non-essential (like all non-restrictive clauses), but it is important.

In the second example, the non-restrictive clause is neither essential nor important. It’s an irrelevant idea that comes out of nowhere.

When you’re describing the location of an office, it’s completely irrelevant what small features it used to have. We need to rewrite this sentence.

Re-write: The office is located in the center of downtown. It used to have a daycare and cafeteria.

Now we’ve got two logical sentences, each containing their own idea.

And on and on and on

Conjunctions, especially “and”, frequently sneak extra ideas into sentences.

Example: Cedric has red hair and freckles, and he plays soccer every Saturday, but he doesn’t like any other sports except hockey.

This sentence tries to describe Cedric’s appearance, what he does, and his interests, which is more than one sentence can handle.

His appearance is completely separate from the other two ideas, so it definitely gets its own sentence.

Break it up: Cedric has red hair and freckles.

Since what Cedric does is related to his interests, we can combine those ideas into one sentence.

Re-write: He plays soccer every Saturday, but he doesn’t like any other sports except hockey.

While the ideas are now fine, the wording makes this sentence clunky. Changing the second half makes it easier to understand.

Re-write: He plays soccer every Saturday, and the only other sport he likes is hockey.

If you’re using a comma and a conjunction, you can always use a period instead, so check how closely your ideas relate to decide which option is better.

See Spot Run

After all this talk of sticking to one and only one idea per sentence, you might be thinking, “So should I write only Dick and Jane sentences?”


There are plenty of lengthy sentences that stick to one idea, while exploring that idea in multiple clauses.

If you’ve got a string of short sentences, look for related thoughts so that you can combine them.

Example: I am a writer. I write online. I mostly write blogs. Sometimes I write product descriptions. I am having lasagna for dinner.

Except for the last sentence, these sentences all relate to online writing. Here are several options for combining them.

Option 1: I am an online writer who mostly writes blogs and occasional product descriptions.

Option 2: As an online writer, I mostly write blogs, and sometimes write product descriptions.

Option 3: I am an online writer. I mostly write blogs and sometimes write product descriptions.

These sentences don’t say anything about lasagna, so they’re all fine.

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