[Mesorah] 2 q on shva

[Dr. B. Rosenberg]

The Ibn Ezra writes in several places, i.e. in Sefer Moznayim, in Sefer
Zahot and also in the Hakdama to his Perush Hatorah (Shita acheret, publ. by
Mossad Harav Kook, which contains also a chapter about dikduk), that since
it is usual for a consonant at the end of a word (exept AHVI, which stand
mute for voyels - "nach nistar"), to have a SHVA NACH (called "nach
nir'eh"), the minhag of the Menakdim is to omit this SHVA (being obvious). 

Ibn Ezra mentions as the only exeptions: Tav and Kaf at the end of a word,
indicating as a reason the need to differentiate between lashon zachar and
lashon nekeva. Amarta (m.) v. amart (f.), zar'echa (m.) v. zar'ech (f.). If
one would omit the SHVA, the reader could think that lashon zachar was meant
and the kametz just forgotten. According to Ibn Ezra one would also write
the SHVA in the word (Ruth 2,9): vezamith, although today's minhag is to
write it only in a tav with daghesh.

- Berysz Rosenberg