A participial phrase can only move about in the sentence when it both
modifies the subject and is nonrestrictive, and a nonrestrictive element
(word, phrase, or clause) is always set off from the rest of the sentence
with a comma or commas.

Thus (in the three standard positions)--

     Seeming deserted, the unpainted house stood on the hill.

     The unpainted house, seeming deserted, stood on the hill.

     The unpainted house stood on the hill, seeming deserted.


Although there is no danger of misreading the phrase as applying to
anything else in the sentence, its relationship to the noun it modifies
(viz. being restrictive or not) is expressed by that comma.

Compare these variations--

     John washed the car, standing in the driveway.

     John washed the car standing in the driveway.


In the first sentence, the comma alone tells you that the sense of the
sentence is--

     John washed the car, while/as he was standing in the driveway.

That or its elliptical counterpart: while standing

This movable participial phrase (capable of moving just before the noun,
just after the noun, or to the end of the sentence) must in all of its
locations yet refer to the subject of the sentence in a nonrestrictive
relationship.  Wherever it moves, it is set off by a comma or commas.

In the second sentence, by contrast, the absence of the comma tells you
that the sense of the sentence is this--

     John washed the car that was standing in the driveway.


No comma.  No movement.  Restrictive, modifying the noun it stands closest to.

Notice too that the phrase in the first sentence seems, at least in this
position, to have an adverbial sense with respect to the noun it modifies
(note the incongruity of an adverb modifying a noun), while in the second
sentence it is clearly adjectival.

I'm still puzzling through this whole issue of when a participial phrase is
adverbial and when adjectival.  In a sentence like the first one above,
notice that if the phrase moves to follow the noun, it can be adjectival
(thought might still be construed adverbially), but that if it moves to
precede the noun, it again seems more clearly adverbial.

Thus . . .

     John, standing in the driveway, washed the car.

might be construed either as--

     John, who was standing in the driveway, washed the car.

Or as--

     John, while/as he was standing in the driveway, washed the car.

While, by contrast . . .

     Standing in the driveway, John washed the car.

can really only be expanded to--

     While/as he was standing in the driveway, John washed the car.

And thus not (seemingly) adjectival at all.

Partly this has to do with the mechanics of relative clauses.  Adjectival
participial phrases ought to be capable of expanding to relative clauses.
But relative clauses can *only* follow the nouns they modify, whereas
participial phrases (when nonrestrictive) can shift about a bit.

I have come to the conclusion that one cannot always say, point blank, that
a participial phrase (or a single-word participle) modifies a noun.  What
one can always say is that the noun in question is the phrase's *subject*.
And that, without it, the phrase would dangle.  (As is true of all
verbals.)  But when the participial phrase has adverbial force with respect
to the sentence, though that noun is its subject, that noun seems less
modified than spoken about.

    Sitting by the window in the heat of the sun, the nine-year-old watched
the passers-by below.

     The cold passed reluctantly from the earth, and the retiring fogs
revealed an army stretched out on the hills, resting.

 "Sitting by the window . . ." seems to have more to do with the manner or
location in which the nine-year-old did what she was doing than pointing
out something about that nine-year-old herself: not the nine-year-old *who*
was sitting, but the nine-year-old *while* sitting.  Likewise, "resting"
seems to remark not upon the army itself, in the way that "stretched out on
the hills" does (which army?  the one stretched out on the hills), but upon
what they were doing while there.

Sometimes participial phrases seem clearly either adverbial or adjectival;
sometimes they squint, seemingly capable of being interpreted either way.
But if not always requiring a noun to modify in the conventional sense,
they always (as verbals) require a noun subject about which they comment in
some way.  Otherwise, they dangle.  And whether adverbial or adjectival,
all participial phrases follow the standard comma guidelines with respect
to being restrictive (no commas) or nonrestrictive (commas).

That's my take on it anyway.


Odile
. . . Trained by Martha

(Anything misleading or misconstructed, however, is the result of my own
faulty explanations or flawed reasoning.  Or sheer oversight.)


____________________

>"The unpainted house stood on the hill, seeming deserted."
>
>"The cowboy walked down the street, trailing a roll of toilet paper."
>
>The participle phrase at the end of each of the two sentences above is
>nonrestrictive.  Nonrestrictive participle phrases are set off by commas.
>Therefore, the two participle phrases are set off by commas.  But
>something in me wants to strike those commas.  I gues my reasoning would
>be that in these cases the participle phrases are set off by intervening
>words and are therefore not in danger of seeming restrictive as they would
>if they were right next to the nouns they modify.  (Whether they really
>modify those nouns is another question; they seem so adverbial.)