Punctuation Point: Joining Independent Clauses : Word Count : Thinkmap Visual Thesaurus

Recently, someone asked me about joining two independent clauses to make a compound sentence. She thought such a sentence would need a comma, but she often found them missing. Today, we'll review how to join independent clauses.

First, a couple of definitions. A clause is a part of a sentence that contains a subject and a verb; it may or may not contain other words. An independent clause can stand as a sentence on its own because it contains a complete thought:

I ran.

Alternatively, a dependent clause does not contain a complete thought and can't stand on its own:

Although I was hungry

A compound sentence is two or more independent clauses (sentences) joined together:

President Obama and Korean President Lee failed to reach agreement on the Korean Free Trade Agreement (FTA) before a joint press conference in Seoul Thursday, but both leaders said the two sides will continue to work towards a final consensus in the near future.

What punctuation do you use between two independent clauses? You have a few options, depending on what parts of speech you use to join the sentences.

Coordinating conjunctions. If you use one of the coordinating conjunctions–and, but, for, nor, or, so, or yet–to join two independent clauses, use a comma before the conjunction:

Swift action saves a man's life, but paramedics fear electric-shock victim may have suffered internal burns to organs.
Adverbs. If you use an adverb, such as however, nevertheless, or thus, use a semicolon before the adverb and a comma after:

We expect average subscription prices to stay around current levels in the near term; however, if promotional activities continue longer than expected or new content agreements adversely impact Dish, this could lower our price estimate of $25.84.

Note, however, that if you use therefore or thus and you don't need to emphasize the following clause, you can drop the comma:

The plane took off late due to poor weather conditions; thus we arrived late.
Transition expression. If you use a phrase such as for example, similarly, or namely, use a semicolon before the adverb and a comma after:

After 45 days of no rain, the farmers were worried about their crops; indeed, it was all they thought about.
Just punctuation. You might choose to join your independent clauses with just punctuation; in that case, use a semicolon (as this sentence does), a colon, or an em-dash.

In The Copyeditor's Handbook, Amy Einsohn succinctly lays out the rules (IND stands for independent clause):

IND, coordinate conjunction IND.
IND; adverb [,] IND.
IND; transitional expression, IND.
IND; IND. or IND: IND. or IND–IND.

For a deeper explanation and more examples, check out pages 78-79 of Einsohn's book.

Do you have more questions on joining clauses? Leave a comment below!

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Erin Brenner is the founder of Right Touch Editing, a customizable editing service. She has been an editing professional for over 15 years and is sought after for her expertise in language mechanics. She works on a variety of media in all levels of editing. In addition, she provides bite-sized lessons to improve your writing on her blog The Writing Resource and is the editor of Copyediting.com, which offers advice and training for those who edit copy. Follow her on Twitter at @ebrenner or on Facebook. Click here to read more articles by Erin Brenner.

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Comments from our users:

Quite informative really, thanks very much!

This is helpful stuff for students, but can I ask you a question about your example of a compound sentence?

In "President Obama and Korean President Lee failed to reach agreement on the Korean Free Trade Agreement (FTA) before a joint press conference in Seoul Thursday, but both leaders said the two sides will continue to work towards a final consensus in the near future", I can see your point about using the coordinating conjunction to link the two independent clauses, but how do you deal with the fact that in the second clause you've also got another clause hidden away too?

The clause "the two sides will continue to work towards a final consensus in the near future" is the object of the "both leaders said..." clause, isn't it?

I'm not trying to be picky (honest!), just wondering how you would deal with this with students, because it seems to me that what we might call "traditional" notions of simple, complex and compound sentences don't really hold up very well when we apply more modern clause analysis.

ALL GOOD ADVICE BUT I FIND SOME OF IT OLD-FASHIONED. I BELIEVE THAT LESS PUNCTUATION IS REQUIRED NOWADAYS AND I PREFER TO JOIN INDEPENDENT CLAUSES WITHOUT PUNCTUATION AND TO BREAK LONG INDEPENDENT CLAUSES INTO TWO SENTENCES. WHAT SAY YOU?

I know a Scottish ESL teacher who claims that as long as the subject of both clauses is the same there is no requirement for a comma before the coordinate conjunction. eg: They came at lunchtime and they stayed until dinner. She says you would only use the comma if the subject of the second clause were different: He was late, but his friends were used to it.

Obviously from the comments, punctuation choices are more complex than one might think; however, Erin offers a useful, concise explanation of the conventions, with good examples. It's possible to think of punctuation as an exercise in critical thinking. Why do I see these two thoughts as so closely related they need to be in the same sentence? What exactly IS their connection? Am I continuing to think along the same lines, requiring "and" or "furthermore"; am I changing directions, needing "but" or "however"; or am I moving from general to specific or showing cause and effect? What word (therefore which punctuation mark) captures that relationship? Could I subordinate one of those thoughts to the other? If so, which clause do I keep independent? If, as Faith S. asserts, we should ignore the finer, more subtle connections, what meanings do we lose? Figuring out WHY my brain put these ideas together may be a key to my true contribution to the conversation on this particular topic, whatever it is. The energy may indeed lie right there in that juncture between thoughts, that synapse. Seeing patterns and connections are a sign of intelligence, and thinking about punctuation, a seemingly insignificant exercise limited to linguists and English teachers, can actually clear the cobwebs and help us to understand each other. It's worth the effort to explore the possibilities of punctuation.

Joyce, I enjoyed your comment about how we convey meaning in 'patterns and connections'. Viewed in this light, punctuation is employed to enhance the patterns and clarify the connections. It serves the same purpose as the marks that punctuate a musical score, indicating to the performer changes in rhythm, tempo, and colour. Readers need guidance in order to know when to breathe, what length a pause should be, and when emphasis is required, so that they will flow through the connections correctly and bring out Joyce's patterns in the prose.

If a punctuation mark turns out to be a stumbling block in this process rather than a stepping stone, then it should be deleted -- whatever the rules say.

Good article on a sometimes-confusing issue.
@Joyce — I do what you do; permit issues about punctuation while I'm writing to push back on structure and organization.

Thank you so much, your article sheds light my brain on.Until now I didn't make different between dash and hyphen, obvious I speak about "size".
Concerning coordinations, conjunctions I meet a lote of problems with these in English.
Punctuation Points in French is easy to see for me but in English !!!!.

I liked the article. I loved the music comment. Often I feel there is too little guidance these days in quite long sentances.

What about:

Bill walked the dog and Mary made dinner.

For me, the even balance of the two independent phrases, and the balance of the two events, is better sensed without a comma.

I like to use as few commas as possible and often find that getting a good word rhythm, with built in accents and pauses, means I can get long comma-less runs that make me happy!

A concise, clear and well-written explanation. Thank you.