Editing Niger–Congo languages (section)

==== Vowels ====
Many Niger–Congo languages' [[vowel harmony]] is based on the [ATR] ([[advanced tongue root]]) feature. In this type of vowel harmony, the position of the root of the tongue in regards to backness is the phonetic basis for the distinction between two harmonizing sets of vowels. In its fullest form, this type involves two classes, each of five vowels.<ref name="Morton 2012:70-71">{{cite book|last=Morton|first=Deborah|url=http://www.lingref.com/cpp/acal/42/paper2759.pdf|title=Harmony in an Eleven Vowel Language|year=2012|pages=70–71|publisher=Cascadilla Proceedings Project |isbn=978-1-57473-453-9}}</ref>

{| class="wikitable"
|-
! [+ATR] !! [−ATR]
|-
| [i] || [ɪ]
|-
| [e] || [ɛ]
|-
| [ə] || [a]
|-
| [o] || [ɔ]
|-
| [u] || [ʊ]
|}

The roots are then divided into [+ATR] and [−ATR] categories. This feature is lexically assigned to the roots because there is no determiner within a normal root that causes the [ATR] value.<ref name="Unseth 2009:2-3">{{cite journal |last=Unseth |first=Carla |url=http://www.gial.edu/images/opal/No-7-Unseth-Wolof-Vowel-Harmony.pdf |title=Vowel Harmony in Wolof |archive-url=https://web.archive.org/web/20130903194104/http://www.gial.edu/images/opal/No-7-Unseth-Wolof-Vowel-Harmony.pdf |archive-date=September 3, 2013 |journal=Occasional Papers in Applied Linguistics |publisher=Graduate Institute of Applied Linguistics |year=2009 |issue=2–3 }}</ref>

There are two types of [ATR] vowel harmony controllers in Niger–Congo. The first controller is the root. When a root contains a [+ATR] or [−ATR] vowel, then that value is applied to the rest of the word, which involves crossing morpheme boundaries.<ref name="Bakovic 2000:ii">{{cite thesis |last=Bakovic |first=Eric |url=http://roa.rutgers.edu/files/360-1199/roa-360-bakovic-2.pdf |title=Harmony, Dominance and Control |type=PhD dissertation |publisher=Rutgers, The State University of New Jersey |year=2000 |page=ii }}</ref> For example, suffixes in [[Wolof language|Wolof]] assimilate to the [ATR] value of the root to which they attach. The following examples of these suffixes alternate depending on the root.<ref name="Unseth 2009:2-3" />

{| class="wikitable"
|-
! [+ATR] !! [−ATR] !! Purpose
|-
| -le || -lɛ || 'participant' 
|-
| -o || -ɔ || 'nominalizing'
|-
| -əl || -al || 'benefactive' 
|}

Furthermore, the directionality of assimilation in [ATR] root-controlled vowel harmony need not be specified. The root features [+ATR] and [−ATR] spread left and/or right as needed, so that no vowel would lack a specification and be ill-formed.<ref name="Clements 1981">{{cite journal |last=Clements |first=G. N. |year=1981 |title=Akan vowel harmony: A non-linear analysis |journal=Harvard Studies in Phonology |volume=2 |pages=108–177 }}</ref>

Unlike in the root-controlled harmony system, where the two [ATR] values behave symmetrically, a large number of Niger–Congo languages exhibit a pattern where the [+ATR] value is more active or dominant than the [−ATR] value.<ref name="Casali 2002:29">{{cite journal |last=Casali |first=Roderic F. |url=http://www.journalofwestafricanlanguages.org/Files/pdf/29-1/JWAL-29-1-Casali.pdf |title=Nawuri ATR Harmony in Typological Perspective |archive-url=https://web.archive.org/web/20140330141738/http://www.journalofwestafricanlanguages.org/Files/pdf/29-1/JWAL-29-1-Casali.pdf |archive-date=March 30, 2014 |publisher=Summer Institute of Linguistics |year=2002 |journal=Journal of West African Languages |volume=29 |issue=1 }}</ref> This results in the second vowel harmony controller being the [+ATR] value. If there is even one vowel that is [+ATR] in the whole word, then the rest of the vowels harmonize with that feature. However, if there is no vowel that is [+ATR], the vowels appear in their underlying form.<ref name="Bakovic 2000:ii" /> This form of vowel harmony control is best exhibited in West African languages. For example, in Nawuri, the diminutive suffix /-bi/ will cause the underlying [−ATR] vowels in a word to become phonetically [+ATR].<ref name="Casali 2002:29" />

There are two types of vowels which affect the harmony process. These are known as neutral or opaque vowels. Neutral vowels do not harmonize to the [ATR] value of the word, and instead maintain their own [ATR] value. The vowels that follow them, however, will receive the [ATR] value of the root. Opaque vowels maintain their own [ATR] value as well, but they affect the harmony process behind them. All of the vowels following an opaque vowel will harmonize with the [ATR] value of the opaque vowel instead of the [ATR] vowel of the root.<ref name="Unseth 2009:2-3" />

The vowel inventory listed above is a ten-vowel language. This is a language in which all of the vowels of the language participate in the harmony system, producing five harmonic pairs. Vowel inventories of this type are still found in some branches of Niger–Congo, for example in the [[Ghana-Togo Mountain languages]].<ref name="Anderson 1999">{{cite journal |last=Anderson |first=C. G. |year=1999 |title=ATR vowel harmony in Akposso |journal=Studies in African Linguistics |volume=28 |issue=2 |pages=185–214 |doi=10.32473/sal.v28i2.107372 |doi-access=free }}</ref> However, this is the rarer inventory as oftentimes there are one or more vowels that are not part of a harmonic pair. This has resulted in seven- and nine-vowel systems being the more popular systems. The majority of languages with [ATR] controlled vowel harmony have either seven or nine vowel phonemes, with the most common non-participatory vowel being /a/.<ref name="Morton 2012:70-71" /> It has been asserted that this is because vowel quality differences in the mid-central region where /ə/, the counterpart of /a/, is found, are difficult to perceive. Another possible reason for the non-participatory status of /a/ is that there is articulatory difficulty in advancing the tongue root when the tongue body is low in order to produce a low [+ATR] vowel.<ref name="Archangeli and Pulleyblank 1994">{{cite book |last1=Archangeli |first1=Diana |first2=Douglas |last2=Pulleyblank |year=1994 |title=Grounded Phonology |series=Current Studies in Linguistics |volume=25 |location=Cambridge |publisher=MIT Press |isbn=0-262-01137-9 }}</ref> Therefore, the vowel inventory for nine-vowel languages is generally:

{| class="wikitable"
|-
! [+ATR] !! [−ATR]
|-
| [i] || [ɪ]
|-
| [e] || [ɛ]
|-
| || [a]
|-
| [o] || [ɔ]
|-
| [u] || [ʊ]
|}

And seven-vowel languages have one of two inventories:

{| class="wikitable"
|-
! [+ATR] !! [−ATR]
|-
| [i] || [ɪ]
|-
| || [ɛ]
|-
| || [a]
|-
| || [ɔ]
|-
| [u] || [ʊ]
|}

{| class="wikitable"
|-
! [+ATR] !! [−ATR]
|-
| [i] ||
|-
| [e] || [ɛ]
|-
| || [a]
|-
| [o] || [ɔ]
|-
| [u] ||
|}

Note that in the nine-vowel language, the missing vowel is, in fact, [ə], [a]'s counterpart, as would be expected.<ref name="Casali 2008">{{Cite journal | doi=10.1111/j.1749-818X.2008.00064.x|title = ATR Harmony in African Languages| journal=Language and Linguistics Compass| volume=2| issue=3| pages=496–549|year = 2008|last1 = Casali|first1 = Roderic F.}}</ref>

The fact that ten vowels have been reconstructed for proto-Ijoid has led to the hypothesis that the original vowel inventory of Niger–Congo was a full ten-vowel system.<ref>{{cite journal |last=Doneux |first=Jean L. |year=1975 |title=Hypothèses pour la comparative des langues atlantiques |journal=Africana Linguistica |volume=6 |pages=41–129 |location=Tervuren |publisher=Musée Royal de l'Afrique Centrale |doi=10.3406/aflin.1975.892 }} (Re: proto-Atlantic)</ref><ref>{{cite book |last=Williamson |first=Kay |year=2000 |chapter=Towards reconstructing Proto-Niger-Congo |title=Proceedings of the 2nd World Congress of African Linguistics, Leipzig 1997 |editor-first=H. E. |editor-last=Wolff |editor2-first=O. |editor2-last=Gensler |pages=49–70 |location=Köln |publisher=Rüdiger Köppe |isbn=3-89645-124-3 }} (Re: proto-Ijoid)</ref><ref>{{cite book |last=Stewart |first=John M. |title=Towards Volta-Congo Reconstruction : Rede |location=Leiden |publisher=Universitaire Pers Leiden |year=1976 |postscript=, |isbn=90-6021-307-6 }} {{cite journal |last=Casali |first=Roderic F. |title=On the Reduction of Vowel Systems in Volta-Congo |journal=African Languages and Cultures |volume=8 |issue=2 |year=1995 |pages=109–121 |doi=10.1080/09544169508717790 }} (Re: proto-Volta-Conga)</ref> On the other hand, Stewart, in recent comparative work, reconstructs a seven-vowel system for his proto-Potou-Akanic-Bantu.<ref>{{cite journal |last=Stewart |first=John M. |year=2002 |title=The potential of Proto-Potou-Akanic-Bantu as a pilot Proto-Niger-Congo, and the reconstructions updated |journal=Journal of African Languages and Linguistics |volume=23 |issue=2 |pages=197–224 |doi=10.1515/jall.2002.012 }}</ref>