‘Let’s eat grandma!’

In case you’re wondering about the title, it’s an example that shows why commas are important for conveying meaning.  Having grandma round for dinner has a whole new meaning when the comma is left out.

‘Let’s eat, grandma,’ is so much more friendly and welcoming.  Who would have thought that one little punctuation mark would make so much difference?  Well … grandma, for a start!

The comma has quite a few purposes.  One use is for the vocative; it can be used to separate a clause or phrase from whom it is addressing. So, ‘Good afternoon, Fred’ is an example of this.

Similarly, the comma can be used to separate a clause or phrase from an extra element that doesn’t change the grammatical sense. For example:  ’Bring me a drink, please.’  The ‘please’ makes the command more polite, but grammatically it can be left out.

The first use of the comma we learn at school is in lists.  ’I bought bananas, apples, oranges and pears’ is a classic example (unless you have been taught to use the Oxford comma, in which case you would have written ‘I bought bananas, apples, oranges, and pears’).  However, there are examples where perfectly well-educated adults occasionally forget the comma’s importance.  There is the amusing (and, sadly, probably mythical) example of the doctor listing a patient’s symptoms: ‘abdominal pain, vomiting, headaches, can’t eat diarrhoea…’

Then there’s the comma that separates clauses.  ”The hospital staff, who had received surgical training, had the lowest patient mortality rate’ means something completely different from  ’The hospital staff who had received surgical training had the lowest patient mortality rate’.  The first tells us that all the staff received training whereas the second tells us that only the staff with training had a low mortality rate.  This implies that there were those who had no training and a high mortality rate.

Knowing my luck, I’ll get the junior porter performing my bypass.