Phonological Alternations

Phonological alternations in Sereer are differently characterized depending on the portion of the word they occur in. On the one hand, Sereer has stems that are fairly invariant in size, almost exclusively alternating by way of morphologically determined consonant mutation of initial (or sometimes final) segments. On the other hand, affixes (and especially verbal suffixes) have phonologically determined allomorphs that alternate between the segmental shapes -VC and -C, seemingly motivated by an avoidance of overlong consonant clusters and hiatus. There is a trade-off in phonological content, then, between invariance in terms of shape (in stems, whose segments do change) and invariance in terms of segments (in affixes, whose shape does change).

Stem Morphophonology

Sereer has salient alternations in the initial consonants of noun and verb stems. These alternations appear to be morphologically conditioned in a lexically specified manner, since they occur in several different segmental contexts whose only common element is being within a morphologically derived environment (e.g. plurality in both nouns and verbs; addition of apparent nominalizing suffixes to verbs).

Standard nominal mutations

Certain noun classes exhibit a stem-initial segment alternation between singular and plural forms. This alternation is evinced not only on the noun itself, but also on any adjectives and determiners describing that noun. With one exception (the alveolar fricative s), this mutation pattern is between homorganic segments. Voiced modal stops, prenasalized stops, and fricatives become voiceless modal stops in plural nouns; voiced implosives become voiceless implosives; labial and alveolar approximants /w/ and /r/ become voiced and voiceless modal stops, respectively. All other consonants are invariant between singular and plural forms.

Source consonant class	Mutated consonant	Labial	Alveolar	Palatal	Velar	Uvular	Glottal
fricative	voiceless stop	f > p		s* > c		x > q
prenasalized stop	voiceless stop	mb > p	nd > t	nj > c	ng > k	nq > q
voiced stop	voiceless stop	b > p	d > t	j > c	g > k
alveolar approximant	voiceless stop		r > t
voiced implosive	voiceless implosive	ɓ > ƥ	ɗ > ƭ	ʄ > ƈ
labial approximant	voiced stop	w > b
voiceless stop	-	p	t	c	k	q	'
voiceless implosive	-	ƥ	ƭ	ƈ
palatal/lateral approximant	-		l	y
nasal	-	m	n	ñ	ŋ

• The consonant s is a partial exception to the regularity of the standard nominal mutation, as it is sometimes invariant and sometimes not. When it alternates (on a lexically-determined basis), it does so with the voiceless palatal stop c.

English gloss	Singular	Plural
pile of millet husks	soxon	coxon
village	saate	caate
onion	soble'	soble'
boat	suk	suk

Human noun class

The human noun class presents a major exception to this pattern, and a very unusual one at that: the "tracks" still apply, but in reverse. Nearly all attested mutations hold to this pattern, but there is no evidence yet for the expected alternation: (sg) voiceless stop --> (pl) prenasalized stop.

Reversed non-implosive "track" for the human class:

• (sg) non-continuants --> (pl) continuants, e.g. otew --> rew 'woman/women' (003)
• [hypothetical: (sg) voiceless stop --> (pl) prenasalized stop]
• (sg) voiceless oral stop, non-implosive --> (pl) voiced oral stop, non-implosive, e.g. okor --> gor 'husband(s)' (006)

Reversed implosive "track" for the human class:

• (sg) voiceless implosive stop --> (pl) voiced implosive stop, e.g. oƈoola --> ʄoola 'member(s) of Jola ethnic group' (014)

Affective noun classes

Diminutives/augmentatives ("affectives") also exhibit initial segment mutations relative to the non-affective noun category. Further generalizations await.

Nouns

(discussion on sg./pl. alternations here)

Deverbal nouns: A noun can be formed from (any?) verb by affixing a prefix a- to the verb root, and altering the initial consonant of the root.

verb	meaning	noun	meaning
ret	go	atet	a trip, "going"
ɗing	fence (in)	aƭing	fence
tos	gather manure	atos	pile of manure
piis	draw a line	apiis	line
weʄ	swim	abeʄ	a swim, swimming

Further alternations remain to be seen, but it appears that the same sorts of alternations seen elsewhere in the language are present here (r,d > t ; voiced implosive > voiceless implosives, etc.)

There are some less straightforward alternations involving not only the initial consonant:

rain (v): deɓ
rain (n): ateƥ

slap (v): faɗ
slap (n): ombaƭ

Verbs

The initial consonant of verb roots can vary based on whether the subject is singular or plural. Non-implosives alternate with prenasalized stops, and implosives alternate with their voiceless counterparts. Alternations are mostly, but not completely, predictable (note multiple possible alternations for /s/ and /q/).

sg.~pl.
f~mb
b~mb
w~mb
ɉ~ɲɉ
χ~ɴɢ
ɗ~ƭ
ɓ~ƥ
ʄ~ƈ
r~nd
d~nd
g~ng

Invariant:
j~j
l~l
m~m
n~n
ŋ~ŋ
ɲ~ɲ
p~p
t~t
k~k
c~c
s~s
ʔ~ʔ

We still need to get the sg vs. pl. forms of verbs starting with:
q

It seems that verb roots (as seen with singular subjects) cannot start with voiceless implosives or prenasalized stops.

Postverbal Affixes

A number of postverbal affixes exhibit a morphophonological alternation between a -VC and -C form. The -VC form appears between consonants, or after a consonant at the end of word, and the -C form appears elsewhere.

1st sg. subject: -(u)m

gef-aa-m 'I break'
vs.
gef-aa-n-um 'I break it'

2nd sg. object: -(o)ng

3rd sg. object: -(i)n

Causative: -(i)n

Reciprocal: -(i)r

Itive: -(i)k

Instrumental applicative: -(i)t

Reversive: -(i)t