It's always an interesting question when talking about the meaning
of words. Because Pali has been around for so long one might ask
if you're talking about Modern Pali, Medieval Pali(Commentaries),
or Canonical Pali. At any rate, I think Prof. De Silva takes the
traditional approach to teaching Pali, which is to introduce the
later language first with its more general meanings. In that case
saddhi.m and saha are used interchangeably.
Prof. Warder, I believe, who teaches the canonical language, would
only use saddhi.m in the cases you cite.

Since you have not learned any possesive pronouns, it must seem odd
to have sentences that seem to require them. I think you'll find
however, that after you learn them you still can't use them. This
appears to be a peculiarity of the language that these relationships
are understood from the context.

I have finished the Pali Primer and am now on chapter 16 of Warder's
Introduction to Pali. I'm glad I studied the Primer first but if I
had to do it all over again I would have spent less time with it.
I've found that there is nothing quite like a footnote.
Good Luck to You!
Paul Ô Cuana

--- In Pali@..., "zeb1001" <zeb1001@...> wrote:
> Lesson 3 of the Pali Primer
>
> >Saddhim / saha meaning 'with' is also used with the instrumental
> case. They are not normally used with nouns denoting things.< What
> is the reason for useing Saddhim instead of Saha or Saha instead of
> Saddhim? As below for example?
>
> 1. Samano narena saddhim gamam gacchati.
> The monk goes to the village with the man.
> 2. Putto matulena saha candam passati.
> The son sees the moon with his uncle.
>
>
> Is there any thing in the following that indicate ownership(?) as
in
> his/theirs instead of "the"
>
> 1. Buddho savakehi saddhim viharam gacchati.The Buddha goes to the
> monastry with the/his disciples
>
> 17. Sugato savakehi saha viharam agacchati.The Buddha comes to the
> monastry with the/his disciples
>
> 20. Kumara assehi saddhim gamam dhavanti.The boys run to the
village
> with the/their horses
>
> Thank-you
> Mettena