So. . . Connecting clauses

When reading sample edits in a writing magazine, I’ve recently come across examples where a comma before the conjunction so has been pronounced incorrect.

Since so is one of the FANBOYS conjunctions (which, we are advised, require commas before their use) and since I’m getting a bit rusty myself since I last looked into commas, I’ve investigated further.

FANBOYS is a popular mnemonic for the coordinating conjunctions for, and, nor, but, or, yet, so. However, some of these don’t always require a comma.

Conjunctions and and but were mentioned in an earlier post, where I decided that added (or non-essential) information required added commas but essential information doesn’t. (see Comma Conclusion. )

For the conjunction so there are a couple of tests that can help you decide.

The that-or-therefore test

1. We do all the work so you don’t have to.

2. We do all the work so that you don’t have to.

If you can add the word that there should not be a comma.

3. We do all the work, so call us today for a quote.

4. We do all the work, therefore call us today for a quote.

5. We do all the work. Call us today for a quote.

OK, the word therefore looks embarrassed in sentence 4, but you get the idea: if you can, at a stretch, replace so with therefore, there should be a comma.

A better test. . .

A better test, because it applies to other conjunctions, is whether the two clauses will stand on their own with a full stop (or period) instead of a conjunction. If you can remove so entirely, as in example 5 above (repeated below) there should be a comma.

5. We do all the work. Call us today for a quote.

This holds true for all coordinating conjunctions.

If a subordinate clause is dependent on the first clause and wouldn’t be written on its own, it requires no comma. The first sentence above comes into this category. (Dependent clause = so that you don’t have to).

In the second example above, both clauses are independent clauses. They could have been written as two separate sentences without altering their meaning, so they need a comma when joined with a conjunction. (I was going to type therefore in there but thought I’d labour the point a little more.)

Look at that last sentence again:

“I was going to type therefore in there but thought I’d labour the point a little more.”

If I had phrased it differently, it would have needed a comma.

“I was going to type therefore in there, but I thought I’d labour the point a little more”

You’re getting the idea if you figured that the clauses in the second example can be written as two sentences, while the dependent clause in the first example couldn’t stand alone without adding that I.

So . . . back to FANBOYS

Substituting so that or therefore to test whether so needs a comma (and similar tricks for other conjunctions) can be helpful if you have an issue with a particular word that does a different job in different contexts.

But for a “one size fits all” guide, remember. . .

Independent clauses (comma)

These conjunctions only require a preceding comma when they are joining independent clauses (each with their own subject) that could otherwise stand alone. That comma and conjunction could be replaced by a full stop.

NB: Where there is no conjunction between independent clauses, use a semicolon if you don’t want to separate the sentences – see earlier post: Where Commas Fear to Tread.

6. We do all the work; call us today for a quote.

Dependent clauses (no comma)

Conversely, a dependent clause (whether or not it has a subject) depends for its meaning on the whole sentence being present and doesn’t require a comma.

Or, to put it slightly differently, a dependent clause . . . depends for its meaning on the whole sentence being present, and it doesn’t require a comma.

Gettit?

What punctuation foibles have irked you down the years?

Which quirks of grammar or style do you still wrestle with?