Without using the word or word forms of "motion",describe how you know and object is in motion

You must look at the object either two or three times,
as follows:

1). Look at it the first time.  Make a mental note, or take a photo,
of its location.

2). Wait a short time.

3). Look at the object the second time.  Make another mental note,
or take another photo, of its position.

4). Compare the two photos or mental notes.

5). If the two images show the object in different places, then the object
is in motion RELATIVE TO YOU, and your investigation is finished.  STOP.

6). If the two images show the object in the same identical place, then
you don't know the answer yet.  It might be moving in a circle.  You must
check it out.

7).  Repeat step-1.

8).  Repeat step-2, but wait a different length of time this time.

9).  Repeat step-3.  This gives you a third photo.

10).  Compare the first and third photos.
. . . . . If these are still identical, you can be pretty sure that
the object is not in motion RELATIVE TO YOU.
. . . . . If these are different, then the object is in motion RELATIVE TO YOU.