Neutralization in Spanish
Spanish has three nasal phonemes, viz. /m/ ~ /n/ ~ /ɲ/. A perusal of the Spanish vocabulary reveals that there are no minimal contrasts involving these phonemes when the following sound is a consonant. It turns out, in fact, that the corresponding phonetic segments [m], [n] and [ɲ] are each restricted in terms of the type of consonant before which they can occur. Thus [m] can only occur before bilabials (as in [ˈkampo] campo ‘field’ and [ˈambos] ambos ‘both’), [n] can only appear before alveolars (as in [sonˈrie] sonríe ‘smiles’) and [ɲ] can only appear before palatals (as in [ˈbaɲdʒo] banyo ‘banjo’).These restrictions could in principle be treated as cases of defective distribution, i.e. we could say simply that the phoneme /m/ cannot appear before non-bilabials, that /n/ cannot appear before non-alveolars and that /ɲ/ cannot appear before non-palatals. But by looking at matters in that way, we would miss an important generalization, because the gap in the distribution of each nasal is not at all arbitrary. Rather, some controlling factor seems to be at work, one which requires the place of articulation of a preconsonantal nasal to match the following consonant’s own place of articulation: bilabial with bilabial, alveolar with alveolar and palatal with palatal. This is turn means that the place of articulation feature is not phonemically distinctive for preconsonantal nasals. But that is precisely the feature that formed the basis for distinguishing between /m/, /n/ and /ɲ/ in the first place. What the phonologist would say, then, is that in Spanish the /m/ ~ /n/ ~ /ɲ/ distinction is suspended or neutralized before a consonant. In this case we posit a so-called archiphoneme, which subsumes all of the nasal phonemes when the distinction or opposition between them is neutralized. The symbol for the nasal archiphoneme is /N/. For example, the words campo, insípido and ancho would be transcribed phonemically as /ˈkaNpo/, /iNˈsipido/ and /ˈaNtʃo/ respectively. Their phonetic transcriptions would be [ˈkampo], [inˈsipiðo] and [ˈaɲtʃo].
This particular case of neutralization is also an instance of assimilation, the process whereby adjacent sounds (or sounds close to one another) become more alike. Thus another way of putting matters would be to say that, in Spanish, a nasal consonant that is immediately followed by another consonant assimilates to that consonant (in terms of its place of articulation).
We have so far only considered assimilation to bilabials, alveolars and palatals. But the process is induced also by labiodental, dental and velar consonants, producing the labiodental, dental and velar nasals [ɱ], [n̪] and [ŋ] respectively. These sounds, together with the phonetic context that triggers their occurrence, is illustrated by the following words:
[eɱˈfeɾmo] enfermo ‘ill’
[ˈben̪da] venda ‘bandage’
[ˈbeŋga] venga ‘come on’
Because [ɱ], [n̪] and [ŋ] occur only immediately before a consonant, i.e. only in positions of neutralization, assigning them to one of the nasal phonemes /m/, /n/ or /ɲ/ would be quite arbitrary. Instead they must be assigned directly to the archiphoneme /N/.
Thus /N/ in Spanish has six allophones, viz. [m], [ɱ], [n̪], [n], [ɲ] and [ŋ]. Which of these actually occurs in a given context is determined entirely by the principle of assimilation.
Laterals also undergo assimilation in preconsonantal position, but only under the influence of palatals, as in [koʎˈtʃon] colchón ‘mattress’, and velars, as in [ˈaɫɣo] algo ‘something’. Therefore, using /L/ to designate a lateral archiphoneme, we have the following distributional statement:
/L/ is realized as [ʎ] when immediately followed by a palatal and as [ɫ] when immediately followed by a velar.Finally, the distinction between the vibrants /r/ and /ɾ/ is also neutralized in all positions except between vowels, meaning that we can posit a vibrant archiphoneme /R/. The distributional rule is as follows:
Before other types of consonant /L/ is realized as [l].
/R/ is realized as the trill [r] in word-initial position and after a nasal, a lateral or /s/.Some examples: [reˈlox] reloj ‘watch’, [ˈonra] honra ‘honour’, [alreðeˈðoɾ] alrededor ‘around’, [iɹraˈel] or [iraˈel] Israel, [aˈtɾako] atraco ‘robbery’, [ˈkaɾne] carne ‘meat’.
Elsewhere /R/ is realized as the tap [ɾ].