What do these 3 sentences have in common?
My brother’s friend is an astronaut.
My laptop screen is 15 inches across.
The queen of England lives in London.
The answer is that each sentence associates one noun with another – meaning that they use word forms and positioning to say that there is some relationship between them. The first used the possessive form – brother’s, the second positioned the word laptop before the word screen, and the third used of.
These are the three ways that nouns are associated with each other. Of these, the possessive form, as in the first example, is by far the most popular and the one that you should use when you’re not sure which to. The next most common is the type that we saw in the second example that I call subcategory/category. And the least common and the one you should avoid unless there doesn’t seem to be any other way is the third with the of construction.
As mentioned, the ‘s at the end of brother in ‘brother’s friend’ in the first sentence indicates possession – that ‘friend’ belongs to ‘brother’, which is consistent with how English treats friendships: as possessions. We have friends. They’re ours.
Again, possession is the most common way in which nouns are associated. When in doubt, use this form.
In the second sentence, positioning ‘laptop’ in front of ‘screen’ tells us that the screen is a subtype of all screens – a screen for laptops. The mechanics and function is very similar to when adjectives are used instead, and the most logical thing might really even be to consider nouns like ‘laptop’ in this case, as adjectives. Notice, for example, how similar the adjective ‘flat’ in the compound word ‘flatscreen’ is in form and function. Both of these are actually often classified into one category: compound nouns.
But the most important point is that multiple nouns (and there can be more than 2) constructed in this way define subtypes of types. Other examples include bus stop, airplane, ice cream, etc.
In general, nouns are associated less often this way than by indicating possession, but more often than using an ‘of’ construction.
Parts of wholes
Constructions like ‘the queen in England’ in the third of our example sentences refers to nouns as components of a larger wholes. Nations, a larger whole, can have sovereigns, and in England the queen in this examaple is that component.
The new sheriff of the town came to clean up.
The larger whole of towns naturally have sheriffs or people by different titles who serve similar functions, and ‘the new sheriff’ in this sentence is that part of that whole.
‘Of’ constructions are therefore used the least of our 3 construction types. This is where people have the most problem: using the ‘of’ construction too much. Use it only when you’re absolutely sure you can or don’t see any way to with either of the other two types we’ve talked about.
We’ll get into some of the reasons for this now.
The distinctions between these categories aren’t so clear a lot of the time, with a particularly high potential confusion between possessive and ‘of’ constructions. After all, when something is part of a larger whole doesn’t it belong to it in a sense?
Since there’s overlap in meanings there’s also overlap in use. When we look closely at how the meanings of the three constructions overlap and what this implies for usage: we’ll see the general advice given for usage affirmed:
Use the possessive the most often, followed by the subtype/type construction, with the ‘of’ construction being the one that should be used the least, and even avoided.
‘Of’ -> possessive |
possessive -> of
You can just about always convert an ‘of’ construction to a possessive, but usually can’t do the opposite. The ‘queen of England’ and ‘new sheriff of the town’ have almost the SAME meanings (with the second set putting more emphasis on possession) and come off about AS smoothly as ‘England’s queen’ and ‘town’s new sheriff’. But ‘Mary’s jacket is in the closet’ does not convert very well at all to ‘the jacket of Mary is in the closet’, which would be wrong, actually. These reasons together explain a lot of why it’s better to tend to the possessive when associating nouns.
Subtype -> possessive |
possessive -> subtype
A lot of people want to put sub/type constructions in the possessive. Instead of ‘laptop screen’ they want to say ‘laptop’s screen’, which isn’t strictly wrong, but isn’t good either. It’s anti-fluent and better to avoid, with the guiding principle being that if the sub/type logic fits, use that and not the possessive.
There’s no way to convert a possessive to a sub/type construction unless the possessive is actually a sub/type being used incorrectly as a possessive.
Sub/type -> ‘of’ | ‘of’ -> sub/type
It is even more difficult to convert a sub/type to an ‘of’ construction than it is to convert a sub/type to a possessive construction, which makes it close to impossible to find an example of where this might work. The ‘screen of my laptop’ is already pretty bad, and wrong, but imagine ‘cream of ice’. Maybe for a hipster restaurant. Not for good grammar.
And finally, ‘of’ constructions can, sort of, be converted into sub/type ones. This will generally require changing the subtype noun to an adjective, which raises a good question about whether we’re actually accomplishing the kind of conversion we’re thinking about. In any case, an example from our examples would be:
The queen of England -> The English queen