Anglosaxon genitive - possessive case

The “Anglo-Saxon genitive” or apostrophe + s (‘s) for possessive seems like it is easy to use, but watch out for certain traps.

Let’s start with some easy examples:

 The teacher’s favourite pupil.

There is one pupil and one teacher in this sentence.

You make “teacher” possessive (aka genitive) by adding an apostrophe and an s.

The teachers’ favourite pupil.

There is one pupil who is the favourite of all her teachers. Notice that you pluralize first (teacher -> teachers), then put the apostrophe after the s.

John and Mary’s friend.

The friend is John’s and Mary’s, but you need to put the apostrophe + s after only the second name (i.e. after the last in the list as in the example below):

Peter, Paul, Mary and Jane’s worst nightmare.

If the name already ends in s, then you have a choice. You may either add an apostrophe s or treat the name  as if it were a plural and add only an apostrophe, as in:

Jesus’ disciples OR Jesus’s disciples.

Augustus’ reign OR  Augustus’s reign

Charles’ friends OR  Charles’s friends.

The rule here is to use an apostrophe + s for “ordinary” names (Charles) but just the apostrophe for famous historical names (Jesus, Augustus).

So much for the punctuation, now for the use:

We tend NOT to use the possessive apostrophe + s  for inanimate objects: e.g. table, chair, pen, cigarette, car, wall. We tend to say the leg of the chair  (or the chair leg) rather than the chair’s leg.  A dog, however, is not inanimate, so we have no problem with the dog’s bone, the cat’s whiskers, the dogs’ barking. Basically, if anything is alive or contains living beings (Rome, Italy, the team, the government, the committee, the USA, the zoo)  then we can use the apostrophe s  construction. If it is inanimate, we usually do not.

Is it alive/does it contain living beings? -> Then yes to ‘s for possessive.

Is it an inanimate object? -> Then usually no to ‘s for possessive.

Exception: Expressions of time also  use the ‘s construction: Yesterday’s news, tomorrow’s picnic, last year’s events, in two weeks’ time, in three days’ time.

Clear?  That means that writing, say,  “The article’s main point is that….” is not a good idea. Article is an inanimate noun, so avoid the ‘s, and rephrase it as:  “The main point of the article is that…”

This rule is flexible in that you may well see written “The book’s main argument…”.

Is this wrong? Well, it depends, but I am not going to delve into when you can break the rule I have just set out. You can, but not always, and  if you follow my inanimate-animate distinction, you’ll never go wrong. You can stop reading here, for  the rule as given above  will always work

If you are willing to go deeper into it, then read on. 

The apostrophe -s construction, also called the Anglo-Saxon genitive/possessive, is, as I say, used for living beings, groups of living beings, countries, cities, places  and expressions of time. Yet it can be used, on occasion, for inanimate objects, provided that the inanimate object has been rendered familiar - provided that it has been "humanized", so to speak.  Say you were writing about your computer, and you kept referring in your essay  to the computer  until the word "computer" has become such a familiar presence that it is almost a "friend" to you and your reader. In this case, you could begin to talk about the computer's keyboard, the computer's hard disk and so on.  Once an inanimate object has been familiarized, usually through repetition, then you can break the rule for that object and use the Anglo-Saxon genitive. I tell you this not to encourage the practice, but to explain it for next time you come across an example and begin to doubt the truth of what I was telling you above.  (Nor should you ever forget that many people, including those who are published, do not write very well). 

Sometimes, even without the familiarity achieved through repetition,   an inanimate object may imply a human presence, in which case an 's construction can be justified. Hence, it is possible to write  "The essay's purpose...." because an essay is semi-animate thing, being the result of human effort. Even so, I'd prefer you did not. Like I said, apply the rule as given above, and you'll always be right.