Estonian, which is spoken by some 1.5 million people, is Estonia's official language and a member of the group of languages known as the Baltic Finnic group (which is a member of the Finnic branch of the Finno-Ugric language family). There are two major, identifiable dialects: South Estonian (known as Tartu) and North Estonian (called Tallinn). They are considered separate languages by some scholars. Estonian is a relative of Finnish, which is heard on the opposite side of the Gulf of Finland, and more remotely to the Hungarian language. Estonian has the distinctive characteristic of traditionally having three degrees of phoneme length - short, long, and "overlong". The main difference between long and overlong is related as much to the stress placed on syllables (involving pitch) as duration. In written Estonian, there is no means to distinguish long and overlong vowels.