A number of years ago it was observed that there is more than one type of intransitive verb (i.e. of verbs describing an action, state or change where only one noun is involved – of which many examples to follow). This is true of many languages, including English.

Sometimes, the subjects of intransitive verbs behave like the subjects of transitive verbs (verbs with two nouns involved, as in Lucy plays football, Harry loves Ancient Egyptian etc.). For example, a typical property of the subject of a transitive verb is that it can be described with the verb plus the suffix -er, e.g.:

  • player – “one who plays something”
  • lover – “one who loves someone”
  • writer – “one who writes something”

Some intransitive subjects can also be so described: workertalkerswimmer, runner etc. But others can’t: we don’t say arriver “one who arrives”, dier “one who dies”, beer “one who is” and so forth …

But there is evidence that the subject of many of this latter group of intransitive verbs actually functions a bit like a transitive object. The object of transitive verbs can often be described with a form of the verb called the past participle, placed before the noun, for example:

  • Hannibal destroyed the city (sentence) / the destroyed city (noun phrase describing object)
  • tourists frequently visit this attraction / the frequently visited attraction

Note that often an extra adjective or other modification is required for the sentence to make sense: the loved library is a bit of an odd thing to say but the much-loved library is fine; likewise we probably wouldn’t say the eaten hamburger but we might say the recently eaten hamburger or the half-eaten hamburger.

We can do a similar thing with some intransitive verbs:

  • the sun rose / the risen sun
  • the man fell / the fallen man
  • the recruits arrived recently / the recently arrived recruits

This suggests the subjects of these verbs actually behave like the objects of transitives, as previously discussed. Note as well that these intransitive verbs are amongst those which can’t take the -er suffix, and furthermore that verbs which can take this suffix don’t allow the pre-noun past participle construction: we can’t say the talked man “the man who talked” or the swum woman “the woman who swam”.

This idea that some intransitive verbs at one level really have objects, instead of subjects, is for various complex reasons referred to as the unaccusative hypothesis. Of course, at another level these “objects” do behave like subjects: e.g. in a sentence they usually come before the verb; if they take the form of pronouns they have the subject forms Iheshe rather than the object forms mehimher; etc. Thus we say I fell not fell me, and so on. There are also various complications (which I won’t go into here, because they are, well, complicated) which suggest the unaccusative hypothesis in its simplest form may be inadequate, and that some refinement is needed.

However, the hypothesis still usefully highlights a couple of things which seem to come up again and again in modern linguistics. Firstly, the way things appear “on the surface” may mask other properties. The noun Lucy looks like a subject in both Lucy talked and Lucy arrived, but in fact in the latter it seems also to have some “underlying” object properties which don’t show up so easily. Secondly, close inspection of the details of a language – including details which we might not think obviously relate to whatever it is we’re thinking about – can help reveal these underlying properties. It is this sort of close attention to detail that has allowed many of the advances in linguistics that have been made over the course of the last few decades. And even the complications I just alluded to may be useful here, in helping us come up with an even better theory.