I came across the following grammatical terms and example sentences on Wikipedia:
As an adjectival phrase modifying a noun phrase that is the object of a verb, provided the verb admits this particular construction:
I saw them digging a hole.
We prefer it standing over there.
As an adverbial phrase, where the role of subject of the nonfinite verb is usually understood to be played by the subject of the main clause. A participial clause like this may be introduced by a conjunction such as when or while:
Looking out of the window, Mary saw a car go by.
We peeled the apples while waiting for the water to boil.
Why are the first two sentences said to have adjectival phrases? I think they are adverbial phrases because they are related to time, not quality.
And how are the first two sentences different from the last two?
Best Answer
There are several different kinds of construction here.
First, (1) and (3) involve sense verbs (saw, looking), which have quite specialized syntax.
Second, preverbal order in (3) is possible with some kinds of clause; but not all, as Greg points out.
Third, several of these sentences are ambiguous, and the ambiguity changes with the syntax.
but Standing over there, we prefer it seems to contrast with Anywhere else, we dislike it,
which is not the case with (1) or (4) when inverted.
(3) has no introductory adverb nor subject, just the bare gerund clause, plus fronting;
(4) has no fronting (but would work fine with it, and would not change meaning:
While waiting for the water to boil, we peeled the apples.
One could go on about the differences and possibilities for subject recovery,
but this is enough to cover some of what Greg didn't.