Commas with conjunctive adverbs

Commas with conjunctive adverbs (however, furthermore, etc.)

Most people would probably agree that commas are the most confusing punctuation marks because there are so
many rules dictating when and how they should be used. I will highlight a few of
the errors that I’ve observed to be the most common.

When combining two sentences into one compound sentence, a comma and a coordinating conjunction ( and,
but, or, nor, for, so, yet ) are used.

Example 1: The festival was to be held today, but it was canceled because of the rainy weather. (comma and
coordinating conjunction )

Sometimes writers use words such as however, furthermore, and therefore (these are called conjunctive adverbs ) in place of coordinating conjunctions to combine two sentences into one. This is where a punctuation problem often arises. The mistake writers make is to incorrectly place a comma in place of a semicolon before conjunctive adverbs, as
illustrated in the sentence below:

Example 2: The festival was to be held today, however, it was canceled due to the rainy weather. ( comma preceding
the conjunctive adverb – INCORRECT.

Note: The comma following the conjunctive adverb is perfectly correct and should be left as is. )

A semicolon, rather than a comma, should precede conjunctive adverbs when they link two complete sentences. Note the corrected form of

Example 2 below:

Example 3: The festival was to be held today; however, it was canceled due to the rainy weather. (semicolon preceding
the conjunctive adverb – CORRECT)

Don’t be misled–there ARE situations in which it is entirely correct to use a comma before a conjunctive adverb, as in
the following sentence:

Example 4: The sporting events , however , continued despite the weather.

Note that in this sentence, in contrast to the sentence in Example 3, no semicolon is needed because it is not a
compound sentence.