Voicing refers to the participation of the vibration of the vocal folds in articulation of consonants, thus dividing the consonants to voiced and voiceless (Gimson, 2008, p. 27). Fortis consonants are voiceless; the vocal folds do not vibrate. Collins & Mees (2013) emphasize that lenis consonants are only potentially voiced because the opposition is not as clear as in Czech and Slovak where consonants are divided into classes according to their voicing: voiced and voiceless (p. 57). While lenis consonants keep their full voicing in medial positions, i.e. between vowels and voiced sounds, final consonants are usually almost devoiced (Collins & Mees, 2013, p. 57). The devoicing of final consonants only applies to lenis obstruents – plosives, fricatives and affricates (Collins & Mees, 2013, p. 57).
3.2.1 The role of vowels
English vowels are crucial for the concept of voicing of final consonants. They are much more complex in comparison to the systems of Czech and Slovak vowels. Skaličková (1974) refers to the difference of quantitative features of English vowels according to a following consonant (p. 13). Lenis and fortis consonants are indicated in pronunciation mainly by the length of the preceding vowel (p. 12). Short English vowels [ɪ, e, æ, ɒ, ʊ, ʌ, ə] are very short in pronunciation before fortis (voiceless) consonants; in the position before lenis (voiced) consonant, however, their duration is equal to a long vowel preceding fortis consonant (Skaličková, 1974, p. 12). For instance, comparing the words bit [bɪt] and bid [bɪd], the vowel in the former word is shorter compared to the vowel in the latter word, but the vowels in the words bid [bɪd] and beat [biːt] have equal duration (Skaličková, 1974, p. 12). However, Skaličková (1974) claims that fortis consonant shortens preceding short vowel and lenis consonant lengthens it (p. 12). Roach (2009) states that this is a half-true assertion and that fortis consonant shortens preceding vowel but lenis consonants do not lengthen preceding vowel (p. 29). The evidence for this is based on the comparison of the words right [raɪt], ride [raɪd] and rye [raɪ], where the duration of the diphthong [aɪ] is equal in the words ride and rye but shorter in the word right (Roach, 2009, p. 29). Fortis consonants are longer than their lenis opposites, thus the duration of fortis consonant and a preceding vowel is equal to the duration of lenis consonant and its preceding vowel. In Czech and Slovak, the ratio of duration is different (Melen, 2010, p. 29).
3.2.2 Bilabial plosives /p/, /b/
English /p/ is a voiceless plosive which maintains its opposition to its paired phoneme /b/ in every position, Czech and Slovak /p/ loses its opposition at the end of words (Skaličková, 1974, p. 78). English /b/ is a voiced plosive which is, however, rarely fully voiced in final positions (Gimson, 2008, p. 170). Nevertheless, the opposition to the sound [p] is still maintained, even though the sound [b] is usually partially devoiced in final positions (Melen, 2010, p. 29). Gimson (2008) states that the voiceless [p] is distinguished from the voiced [b] in final positions either by the reduction of length of the sounds preceding [p], or by the presence of some voicing in the sound [b] (p. 166). Thus, the distinction is maintained between the pairs of words such as cup – cub, rope – robe, rip – rib, either by shortening the vowel before the voiceless plosive or partial voicing of the voiced plosive (Gimson, 2008, p. 169). In order to pronounce the final devoiced lenis consonant, vocal chords only vibrate at the beginning of the compression stage of the articulation and there is no release stage. Thus, the speaker does not continue to pronounce the sound [ə] (Roach, 2009, p. 28; Melen, 2010, p. 72).
Contrarily, the opposition of voiced and voiceless phonemes /p – b/ in final positions becomes neutralized in Slovak and Czech, and voiced /b/ is realized in pronunciation as voiceless /p/ (Vachek, 1973, p. 38). Therefore, in pairs of words such as lep (glue) – leb (skull) [lɛp], trup (trunk) – trub (honk) [trʊp], dup (stamp) – dub (oak) [dʊp], the listeners can identify which of the two words is intended only through the context (Vachek, 1973, p. 38; Kráľ, 1984, p. 114).
3.2.3 Alveolar plosives /t/, /d/
The sound [t] is fortis plosive, often with no audible release (Gimson, 2008, p. 171). The English [t] is different from the Czech and Slovak [t]; it differs by the place and manner of articulation, and mainly by its opposition to its lenis counterpart which is maintained in final positions in English but not in Czech and Slovak (Skaličková, 1974, p. 83). Paired voiced plosive to voiceless /t/ is /d/. In final position, it is usually devoiced; however it still maintains its distinction from [d] (Gimson, 2008, p. 171). The difference between the English [d] and Czech [d] is in the place of articulation; the English [d] is articulated by the tongue blade while the Czech [d] is articulated by the tongue tip (Skaličková, 1974, p. 85).
Thus, the Czech pair of words let (flight) – led (ice) is pronounced the same - [lɛt], plot (fence) – plod (fruit) are pronounced the same as well - [plot], while in English, it is important to distinguish between the voiceless and voiced ending, such as in the words plot [plɒt] and plod [plɒd], or bit [bɪt]and bid [bɪd], the distinction is realized in pronunciation by shortening the vowel preceding lenis consonant or maintaining its length before fortis consonant (Vachek, 1973, p. 38).
3.2.4 Velar plosives /k/, /g/
English velar /k/ differs from the Czech and Slovak /k/ in the place of articulation: the tongue tip is touching the base of the oral cavity when articulating the Czech and Slovak [k] but during the articulation of the English [k], the tongue is not touching the oral cavity (Skaličková, 1974, p. 87). Voiceless /k/ shortens preceding vowel and in English, it maintains its opposition to the paired voiced /g/ in final positions. In Czech and Slovak, the phoneme /g/ is a foreign element which usually does not occur in final positions (Skaličková, 1974, p. 86-88). Since Slovak and Czech [g] does not maintain its opposition at the end of words, it is pronounced as [k], as for example in smog [smok], mák (poppy) – mág (magician) [maːk], glg (gulp) [glk] (Kráľ, 1984, p. 114; Skaličková, 1974, p. 87).
It is important to avoid full voicing of [g] at the end of the words in the English pronunciation. Such pronunciation sounds unnatural to native speakers and is even incorrect, for the word bug might sound as bugger [bʌɡə] if the sound [g] is fully voiced at the end of the word (Melen, 2010, p. 29).
3.2.5 Labio-dental fricatives /f/, /v/
Fortis /f/ is a voiceless pair of lenis voiced /v/. In Czech and Slovak, the sound [f] is a foreign element and occurs mainly in onomatopoeic, borrowed and foreign words (Skaličková, 1974, p. 97; Kráľ, 1984, p. 122). It occurs in Czech and Slovak words such as reliéf (relief), šéf (boss), and šerif (sheriff).
English /v/ maintains its opposition in final positions but has little voicing and the fricative noise audible in /f/ is barely audible in final /v/ while the lower lip makes close contact with the upper front teeth (Roach, 2009, p. 40; Collins & Mees, 2013, p. 92). The English opposition between final sounds [f] and [v] depends again on the length of a preceding vowel – fortis fricative shortens it (Roach, 2009, p. 40). Thus, the following pairs of words are distinguished by the duration of a vowel: leaf [liːf] – leave [liːv], laugh [lɑːf] – love [lʌv], staff [stɑːf] – starve [stɑːv] (Gimson, 2008, p. 192).
Czech final /v/ changes to [f] in pronunciation: lev (lion) [lɛf], krev (blood) [krɛf] (Skaličková, 1974, p. 97). Thus, Czech speakers tend to pronounce English final /v/ as [f]. Slovak final /v/ is substituted by a sound similar to [ʊ] in pronunciation (domov (home) [domoʊ], lov (hunt) [loʊ]), and thus Slovak speakers incorrectly pronounce final English /v/ as [ʊ], which is used in their mother tongue (Bázlik & Miškovičová, 2012, p. 56).
3.2.6 Alveolar fricatives /s/, /z/
English alveolar /s, z/ are articulated when the tip or blade of the tongue makes close contact with the alveolar ridge, the air flows along the groove in the tongue which produces the alveolar friction, characterized by sharp hiss (Collins & Mees, 2013, p. 93). The friction for [s] is voiceless; however the articulation of [z] may include some vocal fold vibration (Gimson, 2008, p. 199).
Czech alveolar fricatives /s, z/ are articulated by the tip or blade of the tongue nearly resting against lower teeth, Slovak /s, z/ are articulated in the same way (Skaličková, 1974, p.101; Kráľ, 1984, p. 74).
In English, the opposition of [s] and [z] is maintained, even when the final [z] is partially devoiced, the Czech and Slovak final opposition of [s] and [z] is not maintained (Skaličková, 1974, p. 102; Kráľ, 1974, p. 74). Thus, the following Czech and Slovak words lose the opposition of [s] and [z] in final positions: les (forest) – lez (crawl) [lɛs], ves (village) – vez (carry) [vɛs], kaz (flaw) [kas]. In contrast to English, the duration of the preceding vowel is negligible (Skaličková, 1974, p. 102).
English final /s/ is pronounced as [z] in monosyllabic words which are not accented, such as his, is, has, was, as, in suffix –s in plural nouns and singular third person after vowel or lenis consonant (Skaličková, 1974, p. 104). Thus, Czech and Slovak speakers must be careful to mind the pronunciation of words such as seas [siːz], fees [fiːz], piece [piːs] - peas [piːz], loose [luːs] – lose [luːz]. Speakers should avoid full voicing of final [z] as it may be incorrectly pronounced as [zə] which could lead to the confusion of meanings, for instance the word buzz [bʌz] may be understood as the word buzzer [bʌzə] (Skaličková, 1974, p. 103).
Students also tend to mispronounce words which exist in their mother tongue as well, but the pronunciation is different in English. The words such as university, baseball, consistent are pronounced with [s], however, Czech and Slovak words univerzita, baseball, konzistentní (konzistentný in Slovak) are realized with [z] in pronunciation (Bázlik & Miškovičová, 2012, p. 58)
3.2.7 Dental fricatives /θ/, /ð/
The English sounds /θ/, /ð/ cause considerable problems to Czech and Slovak speakers, as they are sounds not to be found in the Czech and Slovak sound systems. Both sounds are articulated in the same way: the tip and rims of the tongue are lightly touching the edge and inner surface of the upper incisors, the air escaping between the surface of the tongue and the incisors produces friction which is weaker in the articulation of [ð] (Gimson, 2008, p. 195). The aperture through which the air flows is a small slit rather than a groove, thus the fricative noise is at a lower frequency than the one produced in the articulation of [s, z] (Gimson, 2008, p. 195). Lenis member of the pair is devoiced in the final positions, though it still maintains its lenis opposition to [θ] (Skaličková, 1974, p. 100; Gimson, 2008, p. 189).
Since the consonants [θ, ð] are foreign to Czech and Slovak speakers, they tend to replace them with alveolar fricatives [s, z], or alveolar plosives [t, d], or labiodental fricatives [f, v] because the dental fricatives [θ, ð] seem to them as lisping (Gimson, 2008, p. 196; Bázlik & Miškovičová, 2012, p. 60). Teachers sometimes teach their students interdental articulation of the sounds [θ, ð], that is putting the tongue between the teeth. Daniel Jones states that this way of instruction should only be used when students are completely unable to pronounce the sounds [θ, ð] properly and this type of makeshift should be only provisional because the tongue is normally placed behind the teeth in the articulation of [θ, ð] (Skaličková, 1974, p. 99; Roach, 2009, pp. 40-41).
Speakers should distinguish between the consonants [θ, ð] and not replace them with any other sounds as it may lead to confusion of meanings, such as in the words mouth [maʊθ]- to mouth [tə maʊð] – mouse [maʊs], path [pɑːθ] – pass [pɑːs], bath [bɑːθ] – bathe [beɪð] – bass [beɪs], breath [breθ] – breathe [briːð] – breeze [briːz], wreath [riːθ] – wreathe [riːð], booth [buːð] – booze [buːz], myth [mɪθ] – miss [mɪs] – mid [mɪd], cloth [klɒθ] – clothe [kləʊð] – close [kləʊz], seethe [siːð] – seed [siːd] – seas [siːz] (Gimson, 2008, pp. 194-195).
3.2.8 Affricates /tʃ/, /dʒ/
The English sounds /tʃ/, /dʒ/ are the only affricates. A closure formed between the tip, blade and rims of the tongue, and the alveolar ridge and the front of the hard palate creates the obstacle to the airstream while the front of the tongue is raised towards the hard palate, thus the friction is produced (Collins & Mees, 2013, p. 86). In the articulation of [tʃ], the vocal folds are apart, but the articulation of [dʒ] may involve vibrating (Gimson, 2008, p. 186). In the final positions, the sound [dʒ] is devoiced, the primary perceptual cue to the distinction of [tʃ] and [dʒ] is that the voiceless affricate reduces the length of preceding sounds, just as the voiceless plosives /p, t, k/ do, while the length of preceding sounds remains the same before [dʒ] (Gimson , 2008, p. 186).
] and [dž]. Both are articulated in a similar way as the English affricates; in the Czech [
], the tongue is not raised as high to the palate and the contact with the palate is therefore not as wide as in the English [tʃ], the friction is then at a higher frequency in the Czech [
] (Skaličková, 1974, p. 92). Slovak [č, dž] are articulated when the tip of the tongue rises under the upper edge of the gums and touches it on the boundaries of the front and rear gums (Kráľ, 1984, p. 77). The sound [dʒ], or more precisely [dž], occurs mainly in the words of foreign origin in Czech and Slovak. Speakers should pay attention to the correct pronunciation of the sounds [tʃ, dʒ] in syllable-final positions, primarily by shortening preceding sounds before voiceless [tʃ], as the negligence of the opposition may lead to confusion, such as in the pairs of words rich [rɪtʃ] – ridge [rɪdʒ], larch [lɑːtʃ] – large [lɑːdʒ], etch [etʃ] – edge [edʒ], batch [bætʃ] – badge [bædʒ] (Gimson, 2008, pp. 184-185).
3.2.9 Velar nasal /ŋ/
Particular attention should be paid to the English velar nasal [ŋ]. This sound is often replaced in pronunciation by [n] or even [ŋk] in final positions by Czech and Slovak speakers, as the nasal sound does not occur in the two Slavic languages in final positions, it is only an allophone of [n], and occurs exclusively in assimilation before the phonemes /k/ and /g/ (Skaličková, 1974, p. 115; Bázlik & Miškovičová, 2012, p. 77).
The English, Czech and Slovak nasal [ŋ] is articulated similarly in all the three languages: the back of the tongue and the soft palate form a closure, as for /k, g/, the soft palate is lowered and the air escapes through the nose (Gimson, 2008, p. 212; Roach, 2009, p. 46).
Since the Czech and Slovak [ŋ] only exists before the consonants /k/ and /g/ and is usually pronounced as [ŋk] and [ŋg] in these consonantal clusters, as for example in the words banka (bank) [baŋka], tenký (thin) [tɛŋkiː], Anglicko (England) [aŋglɪtsko], sfinga (sphinx) [sfɪŋga], Czech and Slovak speakers tend to incorrectly realize such pronunciation in English words as well, or they even abandon the nasal pronunciation and pronounce it as [n], which may sound uncultivated or as a sociolect (Melen, 2010, p. 37; Bázlik & Miškovičová, 2012, p. 76). Such negligence in distinguishing between [ŋ], [n] and [ŋk] may lead to change in meaning in context, as in the words thing [θɪŋ] – think [θɪŋk] – thin [θɪn], sing [sɪŋ] – sink [sɪŋk] – sin [sɪn], wing [wɪŋ] – wink [wɪŋk] – win [wɪn], ping [pɪŋ] – pink [pɪŋk] – pin [pɪn] (Gimson, 2008, p. 212; Melen, 2010, p. 37).