English Grammar Review
Clauses and Punctuation

Punctuating Dependent Clauses

There are four main rules for punctuating dependent clauses.

Rule 1 - When the dependent clause precedes the independent clause

In this simple case, we separate the clauses with a comma.

If we choose Kuala Lumpur, we will have better access to our suppliers.

Rule 2 - When the clause is preceded by an attribution

Sometimes we write sentences that begin with an attribution.

She believes that ...
He said that ...
We know that ...

The general rule is to use the same punctuation that we would have used had the attribution not been there at all.

Before we decide about the project, we must consider the risk.

Alya suggested that before we decide about the project, we should consider the risk.

Here we are considering the attribution to be part of the introductory dependent clause, an add-on. Things change when we want to add the attribution but at the same time we want to strongly emphasize the original dependent clause.

Alya suggested that, before any decision about any project, we must consider the risk.

Here we made the dependent clause into an interrupting clause to highlight it. Sometimes the interruption is by choice; we simply want to emphasize something. But sometimes the clause is by itself an interruption, as if we were clearing our throat in the middle of a sentence.

Alya suggested that, as we all know, we must consider the risk.

Try not to do that too much.

Rule 3 - When the clause is the actual subject

It's easy to write a sentence that starts with a clause that sounds like an introductory adverb clause, but is actually the subject of the sentence.

Question: How do I spot a clause that is the subject?

Answer: Replace the dependent clause with the letter X. If the word after X is a verb, you may have a clause acting as the subject.

Whatever Mohamed decides to do, he needs us to support him.

X he needs us to support him.
[next word is not a verb]
[it's a pronoun, the subject]

Whatever Mohamed decides to do is no concern of ours.

X is no concern of ours.
[next word is a verb]
[the clause is the subject]

Note: When a clause is the subject, we do not follow it with a comma like we would for an introductory clause.

Rule 4 - When the clause is essential to the meaning of the sentence

Question: What about a dependent clause in the middle of a sentence? It should always be offset by commas, right?

Answer: Not always. When the dependent clause contains essential information, it is not set off by commas.

Zikri's suggestion that we hold off on buying might be good advice.
[essential information]

With a slight rewrite, we can identify which suggestion and turn the dependent clause from essential to non-essential.

Zikri's final suggestion, that we hold off on buying, might be good advice.

Question: What should I do when my dependent clause contains essential information, and I want it to go in the middle of my sentence, but it also reads like an obvious interruption?

Answer: Avoid making things so complicated. Rewrite the sentence. Try to be less concerned about your preferences for writing and more concerned about the reader's ease of reading. Do the work so they don't have to.

Lesson: Punctuating Dependent Clauses
Module: Clauses and Punctuation
Course: English Grammar Review