Lenition of voiced stops in Kurdish

1 Introduction

Lenition is usually broadly defined as a type of weakening process between sounds (Salmons 2021: 37). A most typical instance would thus be one of ‘voicing’, whereby, for example, a voiceless stop /t/ changes to a voiced stop /d/. Such phenomena, along with others such as sound assimilation, are among the most common segmental interactions (Odden 2005: 239; Salmons 2021: 37). As processes stemming from and interacting with the phonological system of language, they are tightly connected to sound contexts, requiring thus a minute description and analysis of the sound distributions in any language. As with any change, lenition is also crucial in understanding the historical development of a language.

Kurdish is also characterised by a large number of lenition phenomena. Lenition has been studied as part of almost any treatment of Kurdish phonology, whether synchronic (e.g., Haig and Öpengin 2018; MacKenzie 1961a; McCarus 2009; Öpengin 2016) or diachronic, with the aim to situate Kurdish within Iranian dialectology (e.g., MacKenzie 1961b; Paul 2008). However, to the best of our knowledge, a systematic approach to lenition phenomena in Kurdish has not been undertaken. The present study aims to identify instances of lenition both in the history of the language and in current Kurdish varieties across the vast zones they are spoken. Some description of the history of Kurdish and the current distribution of its major varieties is thus in order.

Kurdish refers to a group of West Iranian varieties spoken at the intersection of western Iran, northern Iraq, north-eastern Syria, and south-eastern Turkey (see Figure 1). Kurdish is generally divided into three major subgroups: Northern Kurdish (NK), Central Kurdish (CK), and Southern Kurdish (SK). NK, otherwise called Kurmanji, is the largest group regarding the number of speakers and geographical span. CK (or Sorani) has long been promoted as a standard language in the semi-autonomous Kurdish region of Iraq. SK is spoken in Ilam and Kermanshah provinces in the Iranian side, and neighbouring areas in Iraq. Each major variety is further divided into dialect groups. NK dialects are generally divided into three main zones (see Figure 1) as Northern, South-Eastern, and Western (Haig and Öpengin 2018). CK can be classified into three zones: Northern CK dialects bordering the NK zone; Southern CK dialects bordering the Gorani and SK dialects; and Central dialects, spoken between Sulaymaniyah and northern dialects. The situation of SK dialectology is even more complex. Fattah (2000) classifies SK into seven “important branches”, roughly corresponding to the urban localities in which the varieties are spoken.

When used in a broader sociolinguistic sense, the term Kurdish also encompasses related West Iranian languages, Zazaki and Gorani. While sharing features with Kurdish, these languages exhibit developments that differentiate them from Kurdish (Paul 2008). Nevertheless, these two groups have had a significant role in the development of Kurdish. For instance, MacKenzie (1961b) suggests that the split between NK and CK is the result of the convergence of a part of Kurdish with Gorani, resulting in the formation of CK. In this study, we use the term ‘Kurdish’ to encompass ‘linguistically Kurdish varieties’ NK, CK, and SK, while the term ‘Kurdic’ also encompasses closely related West Iranian languages Zazaki and Gorani that belong to the Kurdish socio-cultural sphere. Zazaki is assumed to be internally classified into three subgroups: Northern Zazaki, spoken around Dersim; Southern Zazaki, spoken around Siverek; and Central Zazaki, spoken around Bingöl and Muş. Gorani dialects are generally classified into two groups: conservative Hawrami dialects, spoken in the mountainous Hawraman region, and peripheral Gorani dialects, scattered across the SK and CK speech zones, especially in Iraq.

In traditional Iranian philology, the Kurdic group belongs to the Northwestern branch of Iranian languages. Within Kurdic, Zazaki and Gorani exhibit Northwestern features par excellence, whereas Kurdish lies at an intermediate position between the Northwestern and Southwestern poles (Paul 1998). Varieties of Kurdic do not descend directly from any known Middle West Iranian (Middle Persian, Parthian) or Old Iranian (Avestan, Old Persian) languages.

To identify both inheritance and possible convergence effects, we investigate lenition processes not only in ‘linguistically Kurdish’ varieties of Northern, Central and Southern Kurdish but also in other two major varieties of Gorani and Zazaki, which, in addition to being part of the geographical Kurdish zone, are historically and socio-culturally closely related to Kurds (see Haig and Öpengin 2014 for a discussion on defining Kurdish).

The five-way distinction between Kurdic language groups allows us to set a point of departure for studying lenition. However, the linguistic history of the region is more complex. It is generally supposed that Gorani was once spoken in a much larger terrain and that the remaining Gorani islands in Figure 1 reflect an earlier linguistic situation in the region (see MacKenzie [1961b] and Khan and Mohammadirad [2023] for a recent discussion). This is corroborated by reports of language shift from the vernaculars of Gorani to CK and SK in recent history (cf. Leezenberg 1992; Mahmoudveysi 2016; Mohammadirad 2024). This has significance for our discussion here since phonological features are expected to be transferred as substratum effects through a process of language shift into the recipient language (see Section 5).

Data from these five major Kurdic varieties are further compared with contemporary Western Iranian languages and Middle and Old Iranian stages. The diachronic development of language in relation to lenition cases is described by incorporating findings of previous studies but primarily by composing our comparative tables. The synchronic data on Kurdic varieties, on the other hand, comes from three sources: (i) a questionnaire developed within the framework of the “ALHOME” project at the University of Cambridge^[1] for studying morphosyntactic and phonological variation within Kurdic^[2] (the phonological section of the questionnaire covers, among other features, the reflexes of voiced stops in different positions within the word in 57 dialects within the Kurdic-speaking zone); (ii) descriptive grammars and available text corpora of individual dialects;^[3] (iii) the authors’ first-hand native knowledge of contemporary dialects of Kurdic. The transcription of the Iranian data follows the standard system in Iranian philology (cf. MacKenzie 1971), where vowel length is marked by a macron, regardless of the status of length as phonemically contrastive in investigated dialects. Other symbols differing from IPA equivalents are as follows: č [ʧ], j [ʤ], š [ʃ], ž [ʒ], y [i], ‘ [ʕ]. Emphatics are marked by an underneath dot, while aspiration, where contrastive, is marked by an apostrophe. Examples brought from other languages have their original transcription unmodified.

The article is structured as follows. Section 2 presents definitions and key distinctions made in lenition literature, especially along the lines of positional conditions on lenition and its differential status as belonging to a completed diachronic process versus a synchronically active process. Section 3 presents a number of lenitions in the history of Kurdish, though admittedly, in the absence of deeper-historical attestation of Kurdish, the analysis is necessarily superficial and speculative. In Section 4, we present three processes of lenition with synchronic relevance, proceeding from the history of the change to a minute description of the phonological environments triggering or blocking the change and its geographical expansion. Finally, Section 5 discusses the outcomes concerning the conditions of lenition and the contact effects on lenition.

2 Lenition: conditions and constraints

Lenition, as defined above, in practice, subsumes various types of sound changes, such as voicing (e.g. p > b), spirantisation or fricativisation (e.g. b > v), approximantisation (e.g. b > w), debuccalisation (i.e. a segment’s losing of its oral articulation to become glottal, e.g. x > h), and loss or complete elision (e.g. w > ø) (Blevins 2004: 145; Honeybone 2012: 775). One can add to these other phenomena involving weakening, such as deaspiration where an aspirated sound loses its aspiration to become unaspirated (e.g. pʰ > p). Despite their apparent diversity, these are seen as instances of a single phenomenon of ‘lenition’ (Bauer 2008: 606). Honeybone (2012: 775) lists three reasons for the continued use of the term in this general sense: one significant difference of lenition from other segmental changes is that the ‘place of articulation’ of the segment undergoing the change remains unchanged, except in debuccalisation; lenition usually applies to a whole natural class of segments (e.g. all voiceless stops); and finally, they are cross-linguistically common.

Several aspects are claimed to be shared in all these types of change, such as loss of segmental material, increase in sonority, and ease of articulation. However, a more principled description of the interconnectedness of such sound changes relies on a notion of phonological ‘weakness’ on a continuum, along which sounds are assumed to progress diachronically. Thus, the so-called ‘lenition trajectories’ have been proposed, such as in Lass (1984: 178), where lenition is conceived broadly as any change along the sonorisation and ‘opening’ dimensions (i.e. stops > affricate > fricative > approximant > zero).

Various crosslinguistic sound changes have been documented to illustrate these overarching descriptive tenets of lenition trajectories and phonological environments. Spirantisation of stops has been observed in various Romance languages (Carvalho 2008), including some Romance dialects of Italy (Marotta 2008). Describing the spirantisation in the dialects of Tuscany, Marotta (2008) observes that while in the northern Italian dialects, voiceless stops weaken via voicing, in the central Tuscany dialects, lenition through spirantisation applies to all stops, both voiced and voiceless, with p, b, t, d, k, g changing to ɸ, β, θ, ð, x/h, ɣ, respectively. The phonological environment conditioning the process is a postvocalic position, such as maɣro ‘thin’ (cf. Standard Italian magro), which is a typical weak position. Lenition is thus blocked after consonants and in gemination. Crucially, the scope of lenition is the utterance or intonational phrase (Marotta 2008: 242) crossing over lexical boundaries such as la θɛsta ‘the head’ (cf. Standard Italian la tɛsta).

Besides the direction of the alternation in the sounds, the phonological environments have also been observed as crucial determinants of lenition (Escure 1977, cited in Bauer 2008: 616). For instance, Lavoie (2001: 31–32) shows that voicing is cross-linguistically common only in intervocalic positions. Phonological environments are thus divided into “weak” and “strong” positions (Honeybone 2012: 775). In line with the notions of lenis and fortis, weak positions promote lenition, whereas strong positions disfavour lenition, instead retaining or promoting fortis.^[4]

Weak positions include intervocalic positions as well as codas. The intervocalic position is further divided into stronger and weaker environments. A strong environment occurs when the vowel following the segment is stressed. In other words, the segment is foot-initial [v__v́], e.g. Gorani ʕā y át < ʕā d át ‘habit, custom’. The weak environment is in place when the vowel following the segment is unstressed, that is when the segment is foot-medial ([v́__v], e.g. foot-medial glottalization of voiceless alveolar stop (t > ʔ) in the Cockney dialect of English: wáter > wáʔer). The relevant coda positions are pre-consonantal [__.c], e.g. SK qayr < gadr ‘esteem’, and post-vocalic word-final [__#], e.g. SK yā y < yā d ‘memory’.

On the other hand, strong positions disfavouring lenition are the two types of syllable onsets as word-initial [#__] and post-coda environments [c.__], e.g. Gorani /řoj.yār/ < /řoj.gār/ ‘sun’. Lenition in the post-coda slot is sensitive to the sonority of the preceding consonant; this can explain the lenition of g to y in řoj y ār.

Crucially, certain lenition types occur more in certain weak environments. Thus, while fricativisation occurs intervocalically, debuccalisation is common in the coda position. As a predictive implication, a case of lenition may occur in both weak and strong positions but never only in strong ones.

A third and final aspect of lenition to be considered here is its relation to diachrony and synchrony. As a synchronic process, lenition is seen in the surface distribution of the segment, much like typical instances of allophony conditioned by the environment, without being part of the underlying representation. As a diachronic process, however, the change involves “the reanalysis of underlying representations based on surface forms” (Honeybone 2012: 774). Thus in the so-called “medial-d spirantisation” (i.e. /d/ > /ð/, as in moder > mother) in late-Middle English period, the change has become part of the underlying representation in all varieties of English and, although phonological environments ultimately shape it, the relevant phonological environment does not trigger the same change: that is, it occurred in words with a following rhotic, but excluded intervocalics as Middle English sadel – Present-Day English saddle, or preconsonantal codas (wedlock) and geminates (bladder), leading to the fact that the two sounds in question are contrastive in the language. It should be noted that the historical or completed cases of lenition and the synchronic processes are seen as different stages in the life cycle of phonological processes, not as essentially distinct phenomena (Bermúdez-Otero and Trousdale 2012; Honeybone 2008; Honeybone 2012).

A synchronic process of lenition in English concerns the so-called ‘flapping’, found in most American English dialects, whereby an alveolar stop t, d, is changed to an alveolar flap [ɾ] in (foot-medial) intervocalic position, as in [ˈbɑɾəm] ‘bottom’ and [ˈmɑɾəm] ‘madam’ (Honeybone 2012: 777). This lenition clearly follows from both the lenition trajectory and phonological environments since a flap is more sonorous than stops, while the environment is the weaker/unstressed intervocalic position.

In the immediate Kurdish region, a case of historical lenition fitting more neatly into the ‘natural class’ behaviour of leniting sounds is the fricativisation of Neo-Aramaic interdental stops. Here the historical interdentals /t/ and /d/ initially had fricative [θ] and [ð] as allophones in postvocalic environment, yet in time they became ‘phonemicised’, thus became part of the underlying representation, giving these two sets of sounds contrastive status, illustrated by the pairs šata ‘year’ – šaθa ‘fever’ and guda ‘wall’ – guða ‘churn’ (Khan 2018a: 312).

Given this background, in this paper, we distinguish between lenition as a diachronic process versus a synchronic process across Kurdic. The main criterion for considering a lenition process as diachronic/old is that all varieties have undergone it. In contrast, synchronic lenition is an ongoing process, shown by the fact that it continues to be an active process in particular dialects while it has stopped being a phonological process in others. As it will be seen, such an approach proves to be useful in understanding the lenition processes within Kurdic varieties under investigation. Nonetheless, the picture is unclear in some cases, and borderline cases are attested. For instance, it is not easy to tell the age of a borrowed word in Kurdic and whether its lenited segment falls under the diachronic or synchronic lenition. The Turkish borrowing for ‘father’ shows lenition in most of NK and CK, and SK, as bāv, bāwk, and bāwg, respectively, except for the Trans-Zab Kurdish dialects, which correspond to the south-eastern NK and northern half of CK, where the /b/ is preserved, as bāb. Similarly, sag ‘dog’, presumably borrowed from Persian, exhibits variation in the realisation of post-vocalic g in modern varieties of Kurdic (see example 25). Here, the lenition of g depends on the period in which individual Kurdic varieties have borrowed sag, with varieties with the non-lenitied g probably borrowing it later than varieties with lenited and/or elided g.

Our study focuses on the lenition processes in intervocalic and postvocalic slots. As stated, these are weak contexts which favour lenition cross-linguistically. The non-initial lenited voiced stops in Kurdish are derived from non-initial Old Iranian voiceless stops p/t/k that develop into non-initial Middle Iranian voiced stops b/d/g. Wherever relevant, the study also touches on the lenition of voiced stops in strong contexts, that is in word-initial, pre-consonantal, and post-coda slots. To this end, we examine respective lenition processes as much as possible diachronically, synchronically, and across different phonological environments.

3 Lenition in the history of Iranian and Kurdish

This section presents some cases of lenition in Kurdish with diachronic relevance. Some of these cases are often cited by scholars working on Iranian languages to define Kurdish as a phylogenetic group within Iranian dialectology (e.g. MacKenzie 1961b). The oft-cited cases of historical change are that the Middle Iranian word-medial and word-final /m/, along with the older xm and šm combinations, is lenited to a fricative /v/ in NK and a bilabial-velar approximant /w/ in CK, though the latter as a secondary development from an earlier /v/ (MacKenzie 1961a: 220, 1961b: 70). The lexical items in (1) illustrate this change:

In some cases, the lenition cycle is completed with zero, as in south-eastern NK and CK zistan (Cf. NP. zemestān) ‘winter’.

This feature was identified by MacKenzie (1961b) as one of the sole isoglosses distinguishing Kurdish as a phylogenetic group. There are, however, many native words which do not follow this change. For instance, the root for the word ‘tail’ in (1) has gone through lenition in Kurdish, but as a stem in the word dūmāhīk ‘end, rest’ in the south-eastern NK dialects, the bilabial nasal is retained. As lexical stress is usually assigned to a final syllable in Kurdish, this resistance to lenition may have to do with the absence of lexical stress in the syllable. Still, its cognate forms in other NK and CK dialects appear with lenited bilabial-velar approximant as dāwī and duwāyī, respectively, making an only stress-based explanation unsatisfactory.^[6] Likewise, although the Middle Persian word čašm ‘eye’ (Av. čašmān-) has given the form čāv/w ‘eye’ in Kurdish, with lenition, it has retained the bilabial nasal in čam ‘river’, which could etymologically go back to the MP word čašmag ‘spring, source’. The word čamāndin ‘to bend’ in south-eastern NK and CK has resisted lenition, unlike its cognate tawāndin in the rest of NK. Alternatively, it could be that čam and čamāndin did not undergo lenition because they are loanwords from other Iranian languages such as Persian or Gorani, though neither exists in modern Persian.

The same type of varied outcomes also appear in several other items. Thus, although lenited in the root jāw ‘fabric’ (cf. Persian jāme), the sound is retained in a derived word jamadānī ‘male headband’. In the same vein, m is not lenited in other words such as zamāwand ‘wedding’ (which is based on the word zāwā ‘groom’), gōm ‘pond’, zōm/zōma ‘camping site’, sāmāɫ ‘clear sky’, etc. Despite these exceptions, there are enough reflexes of the sound illustrating the lenition m (xm, šm) > v in Kurdish.

This sound change is considered to be active for some time after the arrival of Islam among the Kurds since it applied to certain religious Arabic borrowings too, such as silāv/slāw ‘salam’ (< salām) and jivāt ‘community, council’ (< Ar. jamāʕat), but also many general words such as havīr/hawīr (< khamīr). More recent borrowings, or re-borrowings, did not show the change, as ‘alimāndin ‘teach, educate’ (< ʕlm), and jamā‘at/jimāt ‘community’^[7] or yet the Armenian borrowing āmān ‘plate’ (< աման – aman).

Another case of lenition is f > v/w, with in some cases, a complete elision of a coda-initial f:

Yet another case of lenition concerns the omission of š in the coda (sometimes clusters), triggering developments that sometimes lead to a /h/ (3). It is thus challenging to claim a change š > h. This change has not happened in Gorani and Zazaki, which retain the source consonant except in the reflexes of the word for ‘ewe’, but the north-western Zazaki dialects have the expected variant as mēšin:

4 Lenition in current Kurdish: three instances with synchronic relevance

In this section, we present three cases of lenition within Kurdic that are relevant both diachronically and in the synchronic status of dialects. To this end, voiced stops /b/, /d/, and /g/ are examined across the Kurdish speech zone for their lenition diachronically and synchronically. In each case, different phonological environments are considered, highlighting the contexts that favour lenition across Kurdic. Given the parallel chronology of these voiced stops in Iranian languages, it could be said that *Middle Kurdish sounds /b/, /d/, and /g/ would have come from *Old Kurdish *p *t *k. When discussing the lenition of these sounds in the early history of Kurdish, we mean to interpret the changes to the voice stops in the period roughly following *Middle Kurdish, though, admittedly, it is impossible to date precisely when those changes occurred (see Section 2 for discussion of relevant issues).

5 Discussion

In this paper, we surveyed the phenomenon of lenition in Kurdish. The voiced stops /b/, /d/, and /g/ were examined for this purpose. Following the descriptive model in Honeybone (2012), we distinguished between lenition at an earlier history of language and lenition at the current state of varieties. We have gone into some details to break down the lenition of voiced stops in different contexts. These contexts comprise word-initial (including post-coda slot), intervocalic (both foot-initial and foot-medial contexts), and post-vocalic positions, as well as within coda pre-consonantal and post-consonantal slots.

At an early stage, lenition seems to be a shared innovation that brings Kurdic varieties closer to each other. This is true, especially about the historical lenition of voiced stops in the intervocalic position. The former slot has some relevance for the theory of lenition as Kurdic generally allows weakening in the foot-initial context [v__v́], which is not considered a felicitous context for lenition (Honeybone 2012: 776). Similarly, all Kurdic share the commonality of post-vocalic lenition of stops in inherited lexicon. The outcomes of lenition are total deletion for post-vocalic /d/, fricativisation and approximantisation for /b/, and deletion and approximantisation for post-vocalic /g/, depending on the variety.

While historically, the lenition of voiced stops tends to bring all Kurdic varieties together synchronically, it has stopped to be an active process in the current state of much of the NK and northern dialects of CK. On the other hand, the Kurdic dialects spoken in the CK/SK border zone and neighbouring Gorani dialects have innovated the lenition of stops in different syllabic slots as a synchronic process. The synchronic lenition of /b/ is active in western and northernmost NK dialects, much of SCK and SK dialects, and peripheral dialects of Gorani. In core Hawrami dialects, the lenition of /b/ is not attested. These facts are summarised in Table 1.

Table 1:

Lenition of /b/ as a synchronic process within Kurdic.

The synchronic lenition of /d/ occurs more systematically across Gorani dialects but fails to reach the southernmost SK dialects (Table 2).

Table 2:

Lenition of /d/ as a synchronic process within Kurdic.

Finally, the lenition of /g/ is limited to the immediate Gorani zone of influence and neighbouring SK and CK dialects, as seen in Table 3. This phonological process is limited to the peripheral Gorani dialects but fails to reach the mountainous Hawraman region. Within SK, the change is characteristic of northern and western dialects (see Figure 4). Due to restrictions on its phonotactics, /g/ does not appear in pre-consonantal and post-vocalic slots in the modern lexicon of Kurdic. Hence, these two contexts are absent in Table 3.

Table 3:

Lenition of /g/ as a synchronic process within Kurdic.

As seen from Tables 1–3, the lenition of /b/ is more widespread than that of /d/ and /g/, pointing to distinct development of lenition processes associated with /b/. The outcomes of lenition are approximantisation in the south of the wider Kurdish zone, and fricativisation in western dialects of NK. The typical environments for lenition in these dialects are not only those which favour lenition cross-linguistically – so-called ‘weak positions’ – including post-vocalic slot and (foot-medial) inter-vocalic slots, but also ‘strong positions’, those which disfavour lenition, including post-coda and pre-consonantal slots. Therefore, it can be said that the dialects in the southern half of the wider Kurdish zone have innovated the lenition of voiced stops as a synchronic process, not only in weak but also in strong positions.

An overall picture emerges from the lenition of voiced stops at the synchronic state of Kurdic, allowing us to draw isoglosses, which separate the south of the wider Kurdish zone from the northern part. Interestingly, the southern half of the isogloss corresponds to the historical Gorani zone of speech. As discussed in Section 1, Gorani dialects were once more widespread in the region but gave way to Kurdish over time. It is thus possible that the lenition of voiced stops was first innovated in the vernaculars of Gorani and then spread to the vernaculars of southern CK and SK as a substratum feature. Note that for much of the contexts favouring lenition, Gorani dialects have historically retained the lenited segment. It is thus possible that Kurdish dialects of the region matched with the Gorani phonology through the mechanism Blevins (2017) refers to as the “perceptual magnet effect”. An example case was the lenition of the historical /g/ word-initially for the stem gut- ‘to say’ in southern CK and SK through matching with the equivalent stem wāt- in Gorani.^[38]

However, the above scenario only accounts for part of the data. It cannot explain why, at the synchronic state of dialects, conservative Gorani dialects resist lenition in some contexts, e.g., intervocalically. In contrast, peripheral Gorani dialects show the same effect of lenition as neighbouring CK and SK dialects. For example, intervocalic lenition of /g/ affects SK, peripheral Gorani dialects, and some SCK alike but does not reach conservative Hawrami dialects. Similarly, intervocalic and postvocalic /b/ (e.g., in Arabic borrowings such as xabar ‘news’ and xarāba ‘bad’) undergo lenition in peripheral Gorani dialects but not conservative Hawrami dialects. Here, it is more plausible to assume that lenition was innovated in the vernaculars of SK and then spread northward and affected some peripheral Gorani dialects. Support for this claim comes from the fact that the extant peripheral dialects of Gorani have been kurdicised to a considerable extent in recent times. At any rate, the synchronic diffusion of lenition fails to reach the mountainous Hawraman region, where conservative dialects of Gorani are spoken. This then highlights the effect of geographical barriers on the diffusion of innovation.

We may thus conclude that the synchronic lenition of voiced stops was partly due to phonetic matching with Gorani dialects and partly due to the spread of lenition via SK dialects. It is hard to pin down the chronology of these two processes as much is unknown about the linguistic history of the region. Still, provisionally, it might be appealing to assume that given the larger geographical span of Gorani in the past, the first scenario historically preceded the second one.