Problem 3.1 The sentence

  1. Seems that they're finally getting somewhere.
has a missing subject so, obviously, vernacular English allows missing subjects. But we want to know what the conditions are that license missing subjects. Are they, for example, specific to subjects or are they more general? Looking at more data suggests that the ellipsis rule is more general:
  1. You coming? (= Are you coming?)
  2. Whole thing's wrong. (= The whole thing is wrong.)
On the basis of this data, one might propose that there is a process that allows the deletion of the leftmost element in a spoken sentence. Often, of course, this element will be the subject. If this rule is "phonological," then it may apply independently of the syntactic requirement for sentences to have subjects and obscure its effect.

One way to test this line of reasoning is to look at subordinate clauses, where the subject will not be the leftmost element:

  1. Mary said that *(it) seems that they're getting somewhere.
In these cases the subject is obligatory, So, the fact that (1) is a matrix clause is apparently relevant to the licensing of the missing subject.

Another sentence type we can look at is questions or other inverted sentences, since the subject-aux inversion removes the subject from the leftmost position:

  1. Who will *(you) visit?
  2. Never before have *(we) done anything like this.
Again, the subject is required, supporting the existence of a surface deletion process.

Of course, there are many languages in which missing subjects are possible under broader conditions than in English. These languages require a different analysis.