Welsh /s^/

[David L. White]

> 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

        Probably, though the development may be fairly recent and influenced
by English.

Dr. David L. White