In linguistics, a consonant cluster, consonant sequence or consonant compound, is a group of consonants which have no intervening vowel. In English, for example, the groups and are consonant clusters in the word splits. In the education field it is variously called a consonant cluster or a consonant blend. Some linguists argue that the term can be properly applied only to those consonant clusters that occur within one syllable. Others claim that the concept is more useful when it includes consonant sequences across syllable boundaries. According to the former definition, the longest consonant clusters in the word extra would be and , whereas the latter allows , which is phonetically in some accents. Phonotactics Each language has an associated set of phonotactic constraints. Languages' phonotactics differ as to what consonant clusters they permit. Many languages are more restrictive than English in terms of consonant clusters, and some forbid consonant clusters entirely. For example, Hawaiian, like most Malayo-Polynesian languages, forbid consonant clusters entirely. Japanese is almost as strict, but allows a sequence of a nasal consonant plus another consonant, as in (the name of the largest island of Japan). (Palatalized consonants, such as [kʲ] in , are single consonants.) Standard Arabic forbids initial consonant clusters and more than two consecutive consonants in other positions, as do most other Semitic languages, although Modern Israeli Hebrew permits initial two-consonant clusters (e.g. "cap"; "pumpkin"), and Moroccan Arabic, under Berber influence, allows strings of several consonants. Like most Mon–Khmer languages, Khmer permits only initial consonant clusters with up to three consonants in a row per syllable. Finnish has initial consonant clusters natively only on South-Western dialects and on foreign loans, and only clusters of three inside the word are allowed. Most spoken languages and dialects, however, are more permissive. In Burmese, consonant clusters of only up to three consonants (the initial and two medials—two written forms of , ) at the initial onset are allowed in writing and only two (the initial and one medial) are pronounced; these clusters are restricted to certain letters. Some Burmese dialects allow for clusters of up to four consonants (with the addition of the medial, which can combine with the above-mentioned medials). At the other end of the scale, the Kartvelian languages of Georgia are drastically more permissive of consonant clustering. Clusters in Georgian of four, five or six consonants are not unusual—for instance, (flat), (trainer) and (peeling)—and if