The Joining Comma
The joining comma is only slightly different from the listing comma. It is used to join two complete sentences into a single sentence, and it must be followed by a suitable connecting word. The connecting words which can be used in this way are and, or, but, while and yet. Here are some examples:
- Norway has applied to join the EC, and Sweden is expected to do the
same.
- You must hand in your essay by Friday, or you will receive a mark of zero.
- Britain has long been isolated in Europe, but now she is beginning to find allies.
- Billions of dollars have been hurled into the Star Wars projects, yet we appear to have nothing to show for this colossal expenditure.
- A dropped goal counts three points in rugby union, while in rugby league it only counts one point.
- You must hand in your essay by Friday, or you will receive a mark of zero.
Remember, as I pointed out earlier, you cannot join two sentences with a comma unless you also use one of these connecting words. All of the following examples are therefore wrong:
- *Bangladesh is one of the world's poorest countries, its annual income
is only $80 per person.
- *The British are notoriously bad at learning foreign languages, the Dutch are famously good at it.
- *The proposal to introduce rock music to Radio 3 has caused an outcry, angry letters have been pouring into the BBC.
- *Borg won his fifth straight Wimbledon title in 1980, the following year he lost in the final to McEnroe.
- *The British are notoriously bad at learning foreign languages, the Dutch are famously good at it.
Joining two complete sentences with a comma in this way is one of the commonest of all punctuation errors, but one of the easiest to avoid if you pay a little attention to what you're writing. Either you must follow the comma with one of the connecting words listed above, or you must replace the comma with a semicolon.
Note also that most other connecting words cannot be preceded by a joining comma. For example, the connecting words however, therefore, hence, consequently, nevertheless and thus cannot be used after a joining comma. Hence the following examples are also wrong:
- *Saturn was long thought to be the only ringed planet, however, this is
now known not to be the case.
- *Two members of the expedition were too ill to continue, nevertheless the others decided to press on.
- *Liverpool are five points behind the leaders, therefore they must win both their remaining games.
- *Two members of the expedition were too ill to continue, nevertheless the others decided to press on.
Sentences like these once again require, not a comma, but a semicolon.
The rule is again easy:
- • Use a joining comma to join two complete sentences with one of the words and, or, but, yet or while. Do not use a joining comma in any other way.
Copyright © Larry Trask, 1997
Maintained by the Department of Informatics, University of Sussex