ost entirely of isolated words, we know
scarcely anything about the morphology of the language during this
period. To the middle period belong the ancient poems from the Black
Book of Carmarthen, but the language of these compositions is
evidently much older than the date of the manuscript (12th century),
as it preserves a number of very archaic features. Other important
sources of information for this period are the O. Welsh Laws contained
in a MS. of the 12th century. To a somewhat later date belong the
Mabinogion (14th century MS.), and the prose versions of French
romances published by R. Williams (15th century). In Middle Welsh the
consonant mutations are in general denoted in writing, though not
consistently, and from this period dates the introduction of w and y
(O.W. u, i) to denote vowel sounds. The symbol ll to denote a
voiceless l was already employed in Mid. W. but rh (= voiceless r), dd
(= Eng. th in "thou") and f (= v) either do not appear or only become
regular during the modern period In Mod. W. the orthography is
regularized and does not differ materially from that of the late
medieval documents. In O.W. the old stress on the final syllable (the
historical penult) appears to have been preserved, but during the
middle period the accent was shifted to the penult. In consequence of
this change aw (a) in final syllables is reduced to o in Mod. W., e.g.
Mid. W. _pechawt_ < Lat. _peccatum_, Mod. W. _pechod_.

The comparative wealth of inflection preserved by O. Ir. has almost
entirely disappeared in Welsh. There are only the faintest traces of
the case forms, the dual and the neuter gender. Compared with the
Irish nominal declension according to -o- (-jo-), -a-, -i-, -u-, -s-,
guttural, dental and nasal stems, Welsh only distinguishes the nom.
sing. and plur., the latter sometimes retaining an old formation. Thus
masc. -o- stems show palatal modification, e.g. _corn_, "horn," plur.
_cyrn_ < _*korni_; the plural ending of -u- stems, O. Gaulish _-oves_,
gives O.W. -ou, Mid. W. -eu, Mod. W. -au, e.g. _penneu_, "heads." The
termination _-ones_ of the -n- stems appears as -on. The infixation of
pronominal objects between a verbal particle and the verb itself
continues in use down to the present day as in Breton. In the third
person sing. of the pres. ind. there are instances in the oldest Welsh
of the peculiar alternation between orthotonic and a