('blade of grass'), ('shock'), and krnąbrność ('disobedience'). A popular Polish tongue-twister (from a verse by Jan Brzechwa) is ('In Szczebrzeszyn a beetle buzzes in the reeds'). For the restrictions on combinations of voiced and voiceless consonants in clusters, see § Voicing and devoicing below. Unlike languages such as Czech, Polish does not have syllabic consonants: the nucleus of a syllable is always a vowel. The consonant is restricted to positions adjacent to a vowel. It also cannot precede i or y. (For other restrictions on consonants appearing before i or y, see § Distribution above.) Voicing and devoicing Polish obstruents (stops, affricates and fricatives) are subject to voicing and devoicing in certain positions. This leads to neutralization of voiced/voiceless pairs in those positions (or equivalently, restrictions on the distribution of voiced and voiceless consonants). The phenomenon applies in word-final position and in consonant clusters. In Polish consonant clusters, including across a word boundary, the obstruents are all voiced or all voiceless. To determine (based on the spelling of the words) whether a given cluster has voiced or voiceless obstruents, the last obstruent in the cluster, excluding w or rz (but including ż), should be examined to see if it appears to be voiced or voiceless. The consonants n, m, ń, r, j, l, ł do not represent obstruents and so do not affect the voicing of other consonants; they are also usually not subject to devoicing except when surrounded by unvoiced consonants. Some examples follow (click the words to hear them spoken): ('boat'), → before the voiceless k ('jackdaw'), → before the voiceless k ('also'), → before the voiced ż ('as if'), → before the voiced b ('bush'), → ; rz does not determine the voicing of the cluster ('to replay'), → & → ; w does not determine the voicing of the cluster dach domu ('roof of the house'), → ; the rule still applies across a word boundary In some dialects of Wielkopolska and the eastern borderlands, remains voiced after voiceless consonants. The above rule does not apply to sonorants: a consonant cluster may contain voiced sonorants and voiceless obstruents, as in , , słoń , tnąc . Utterance-finally, obstruents are pronounced voiceless. For example, the in bóg ('god') is pronounced , and the in zajazd ('inn') represents . If followed by a word beginning with a obstruent then the above cluster rules apply across morpheme boundaries. When