Toilet flushing instructions and recursive binary Merge

Spotted in the Duke of Cumberland loos in Whitstable this weekend, this instruction on how to flush the toilet:

Press hard
Both buttons

I interpret this as two instructions:

PRESS HARD. BOTH BUTTONS. 

You could read it as a single instruction ('Press hard both buttons') but it's awkward in English. It would be normal in, say, Spanish, but in English a more idiomatic word order is 'Press both buttons hard', or verb (press) – object (both buttons) – adverb (hard).

The way that this is broken down into two phrases can be seen as support for the idea that syntax comprises a series of operations of recursive binary Merge. That's a technical way of saying that sentences are formed by combining two elements at a time, and combining the resulting component with a new element, still two at a time.

So, for example, we might think of a sentence like Birds eat seeds as being formed as follows:

eat + seeds --> eat seeds
birds + eat seeds --> birds eat seeds

Our loo-flushing example is a little bit more complicated. We don't have a subject, because it's an instruction so there is an implicit 'you' as the presser of the buttons. We definitely want to say that both buttons is a unit (a 'constituent'), which seems intuitively right (there are also ways to test this kind of thing). Then we want to say that Press both buttons is a constituent, with the verb press combining with its object both buttons. Then we would combine that whole phrase press both buttons with the adverb hard, telling us how the action of pressing both buttons should be performed. This makes more sense than saying that the verb press combines with a constituent both buttons hard, which doesn't seem intuitively right. Adverbs tell us how verbs are done, not what nouns are like. So now we have this structure:

both + buttons --> both buttons
press + both buttons --> press both buttons
press both buttons + hard --> press both buttons hard

The fact that the adverb refers to the verb, and not to the noun, also tells us why we get the broken-up instructions in the photo. The adverb, as I said, refers to the verb. We interpret it as referring to the whole verb phrase press both buttons as the thing that has to be done in a hard manner, but in fact it's really the pressing that is to be hard. The whole phrase involves the three levels of recursive Merge (recombining constituents) shown above, giving a final nested structure like this:

[3 [2 press [1 both buttons 1] 2] hard 3]

If we want to make it much simpler, one way of doing that is to remove the recursive part of the operation, and have things combine just once. This means, if you assume that Merge is binary (that things can only combine two at a time and not three or more), that the maximum number of words you can have in an utterance is two. And that's exactly what is happening in the photo: two pairs of words (both buttons; press hard), and their juxtaposition is what tells us that one applies to the other rather than their syntactic combination.

The object of sleep

A while back, I wrote a post about what appeared to be a causative alternation with the verb wait: I said They wait you in the bookshop. In that post, I said 'sleep doesn't have an object', and this is true: it's the prototypical example linguists use of an intransitive verb (i.e. one that doesn't have an object).

Language is a flexible beast, though, and you can get things like I slept the whole night through, where one might argue that the whole night is an object. But this isn't so clear cut, as you might prefer to say that the whole night through is an adverbial phrase modifying the verb slept, the same as if it was I slept all night or I slept for ages.

However, last week I heard an example where sleep definitely did have an object, and it was the same sort of construction as the wait example in my earlier post. I was on holiday at a folk festival with some friends, including an 11-year-old boy. His mum commented on the fact that he'd only had a short nap, and he said I know but it slept me enough. In this sentence, the subject is it (the nap) and the object is me (i.e. the sleeper). I think that's quite cool.

They wait you

Sounds sinister, that title, like a line from a classic ghost story. It's not - I said it, in the perfectly pleasant surroundings of Côte in Covent Garden, talking about the lunch we'd had that day in the London Review Bookshop.

This bookshop is a very nice bookshop with a small selection of linguistics books hidden at the bottom of a small set of shelves in the basement. But I wasn't there to peruse the books. It was lunchtime, I was having a break from seeing Ice Age things at the British Museum with my parents and we needed some lunch before going to see Pompeii and Herculaneum things. There's a very nice cafe in the bookshop, selling home-made sorts of food and a million types of tea. It's small though, and popular, so we had to wait for a table. The waitress suggested we wait in the bookshop and she'd come and get us when there was a free table.

I was telling my aunt about this when we met her later on, and I said:

They wait you in the bookshop.

Wait is not normally used this way, but I liked it so I let it stand. Normally, wait doesn't have an object - that is, (roughly) something acted on by the verb. Sleep doesn't have an object (I slept) but catch does (I caught a rabbit), and eat either can or can't (I've eaten or I've eaten six Jaffa cakes). Wait is like sleep (I  waited). What I said included an object: They wait you (we can ignore in the bookshop for now, because it's optional in the sentence).

Sometimes, we have verbs that change the number of objects they have (in this case from 0 to 1) because of some syntactic difference. This is different from eat, which either has a 'null' object meaning 'some unspecified kind of food' or just has two very closely related meanings.

Wait normally has a subject which is the person doing the waiting: if I say I waited, it's me who's done the waiting. With eat, that subject stays the same whether we add an object or not: I ate or I ate six Jaffa cakes, it's still me who ate something. But look at the sentence above: the subject is not the person who is waiting. When I said They wait you in the bookshop, it's not 'they' who are waiting, it's the object of the sentence, you (=us, in that case). So when I added the object, I also changed the role of the participants in the action.

What I meant by that utterance was, I suppose, They make you wait in the bookshop or They cause you to wait in the bookshop. I've turned it into what linguists, in an uncharacteristic show of naming things transparently, call a 'causative'. It's comparable to grow: I can say either I grew, and then it is me who became larger, or I can say I grew a plant or I grew the profits and then it is something else that I have caused to become larger.

It's also related to something called 'middle voice'. It's called that because it's in the middle between active and passive. If you think about a sentence like The cake cuts well, then the cake is grammatically the subject of an active verb, but the meaning is that the cake is the thing that is cut, and that's the meaning you'd get from a passive form: The cake has been cut. English doesn't do this loads, compared to some other languages, and that's not what's happening with wait above. It's just a similar phenomenon.