One of the most common challenges in business writing today is getting the comma and full stop in the right place. Yes, it’s as simple as that! I see so many commas where there should really be full-stops. The thing is, when you put a comma (when it really should be a full stop) I’ll read along the sentence, then after the comma I’ll figure out it just doesn’t make sense, so I have to re-read from the beginning again to try to make sense of your sentence. This is all taking up too much of the reader’s time. Study some simple rules for the comma and you may help yourself as well as your readers.

As a general rule, we should use a comma:

  • to separate words or phrases in a list.
    Would you like a gold, grey, white or black trim on your new car?
    Writing well takes time, effort and a lot of practice.
    (NB: In a list like this, do not put a comma before the final and.)
  • to separate adjectives qualifying the same noun.
    Please send us a large, self-addressed envelope.
    I enjoy the warm, humid climate in Singapore.
  • to join two clauses that are joined by a co-ordinating conjunction.
    The expansion of our business is a long-term project, and we need an efficient management consultant to help us.
    John has the necessary qualifications, but Dave has more experience.
    (NB: Whether or not you use a comma here will depend on your own preference, the length of the sentence and the amount of separation that you wish to show. In a short sentence where the ideas in the clauses are closely related, you might leave out the comma. In a longer sentence you might put in the comma so that the reader can better absorb what he or she has read so far.)
  • to create parentheses, where something is inserted that either expands on the main sentence or qualifies part of it.
    Mandy Lim, my secretary, will contact you soon to make an appointment.
    The Managing Director, who is overseas at present, has asked me to reply to your letter.
  • to separate phrases and clauses to make your message easier to read.
    We have five different models, each with its own special features.
    Although I agree with the points you mention, I would like clarification on various issues.

Using commas is largely a matter of taste and style, but one thing is for sure – they should not be overused. When I first revised Gartside's Model Business Letters in 1992 many of the letters were full of commas and very long sentences. Take a look at this example:

Unfortunately, if we invest in new machinery, and the market falls again, as it has been predicted, we may, possibly, find ourselves with too much production capacity, and this may, therefore, result in even more serious problems.

While all the commas in this sentence are placed correctly, there are far too many of them and they make the sentence jerky. In today's business writing we should keep sentences short and cut out non- essential commas. For example:

We must give serious consideration to the issue of investing in new machinery. If the market falls again, as it has been predicted, we could find ourselves with increased production capacity. This may then result in even more difficulties.

TIP: A comma represents a short pause. When reading any written messages, don't just see words on paper (or screen) – imagine you are reading the sentences out loud, as though you are speaking to your audience.This will help you to place the commas and full stops correctly.

 Next time: Common problems with commas.