Johanna suggests the probable confusion of the non-finite clause and a
way out of that confusion.

> There is a source of confusion here, namely the fact that the past
> participle and past tense form of 'fix' look exactly the same. What we
> have in this absolute phrase is the past participle, not the past tense;
> hence the difficulty making it into a finite clause.
>
> The way to make clear that a reduced clause is nonfinite is to put it
> into several frames that show that it is not the reduced clause that
> indicates the time at which the event or state (fixing) occurred, but
> rather a tensed verb elsewhere in the sentence:
>
> "I stood still, my whole attention fixed upon the motion of her fingers"
> "I am standing still, my whole attention fixed upon the motion of her fingers"
> "I will stand still, my whole attention fixed upon the motion of her fingers"
>
> The fixedness of attention is located in time by the tense/aspect of the
> sentence's main verb, not by the participle 'fixed'.

>
> Nonfinite means 'not marked for tense'. A nonfinite clause, reduced or
> not, may show _aspect_ (whether the action of the verb is ongoing (-ing)
> or completed (-ed,-en)), but it will not show tense.

Let me suggest explanation.  There is an interesting formal property of
English that can help us determine whether a particular clause is
"marked for tense" or is not "marked for tense."  In English, NOT always
appears after tense, if the clause has tense.

Although both (1) and (2) have the verb stood in them, the difference is
revealed when  both sentences are made negative by inserting NOT.

1) I stood still
2) I have stood still.

3) I did not stand still.
4) I have not stood still.

If stood is really "the same," then we have a great deal of difficulty
in explaining the obvious differences in 3 and 4.

Let's apply this principle to a slightly different version of our
problem sentence.

5) I stood still and my whole attention fixed upon the motion of her
fingers.
6) I did not stand still and my whole attention did not fix upon the
motion of her fingers.

In (5), stood and fixed clearly are marked for tense as revealed in (6).

For the problem sentence (7), we get (8).

7) I stood still, my whole attention fixed upon the motion of her
fingers.
8) I didn't stand still, my whole attention not fixed upon the motion of
her fingers.

Of course, (9) is possible, but then we are really dealing with two
independent clauses.

9) I did not stand still.  My whole attention did not fix upon the
motion of her fingers.

Johanna's admonition is absolutely right.

> It's very important to separate tense from aspect in teaching about verb
> forms and tense/aspect constructions in English.

Fortunately, there is a formal property of English which we can exploit
to make that clear.

Bob Yates
Central Missouri State University