Etruscans

[Jim Rader]

No, it's not really /s/ because it's /s^/.  The digraph <si> is the
usual way /s^/ is written in Welsh.  In native words /s^/ arose at
least dialectally when /s/ and /j/ were in contact, most typically in
combinations of /s/ with the plural ending <-iau> or the verbal
formative <-i-> (with the verbal noun ending in <-io>).  Hence the
use of <si> to denote initial /s^/ in English loanwords, or the rare
Romance loanword such as <siarad>, "speak."

Jim Rader

>         It is not true that /s^/ is necessarily borrowed as /s/ by languages
> that do not have /s^/.  For example, English "shop" has been borrowed into
> Welsh as "siopa", with the /i/ evidently being an attempt to indicate that
> the sound in question was not really /s/.  That the same sort of thing might
> lie behind /tro(s)ia/ is hardly an unreasonable suggestion.

> Dr. David L. White