Slovak () , is a West Slavic language of the Czech–Slovak group, written in Latin script. It is part of the Indo-European language family, and is one of the Slavic languages, which are part of the larger Balto-Slavic branch. Spoken by approximately 5 million people as a native language, primarily ethnic Slovaks, it serves as the official language of Slovakia and one of the 24 official languages of the European Union. Slovak is closely related to Czech, to the point of mutual intelligibility to a very high degree, as well as Polish. Like other Slavic languages, Slovak is a fusional language with a complex system of morphology and relatively flexible word order. Its vocabulary has been extensively influenced by Latin and German and other Slavic languages. The Czech–Slovak group developed within West Slavic in the high medieval period, and the standardization of Czech and Slovak within the Czech–Slovak dialect continuum emerged in the early modern period. In the later mid-19th century, the modern Slovak alphabet and written standard became codified by Ľudovít Štúr and reformed by Martin Hattala. The Moravian dialects spoken in the western part of the country along the border with the Czech Republic are also sometimes classified as Slovak, although some of their western variants are closer to Czech; they nonetheless form the bridge dialects between the two languages. Slovak speakers are also found in the Slovak diaspora in the United States, the Czech Republic, Argentina, Serbia, Ireland, Romania, Poland, Canada, Hungary, Germany, Croatia, Israel, the United Kingdom, Australia, Austria, Ukraine, Norway, and other countries to a lesser extent. Phonology Slovak contains 15 vowel phonemes (11 monophthongs and four diphthongs) and 29 consonants. The phoneme /æ/ is marginal and often merges with /e/; the two are normally only distinguished in higher registers. Vowel length is phonemic in Slovak and both short and long vowels have the same quality. In addition, Slovak employs a "rhythmic law" which forbids two long vowels from following one another. In such cases the second vowel is shortened. For example, adding the locative plural ending to the root creates , not . Slovak has final devoicing; when a voiced consonant () is at the end of a word before a pause, it is devoiced to its voiceless counterpart (, respectively). For example, is pronounced and is pronounced . Consonant clusters containing both voiced and voiceless elements are entirely voiced if the last consonant