Proto-Indo-European languages are the origin of the majority of languages spoken in Eastern Europe. Hungarian and Estonian languages are from the Finno-Ugric group.
The languages of Eastern Europe are, for the most part, Slavic languages - like Russian and Polish. However, other language groups have also found purchase in Eastern and Central Europe. The Baltic languages include Lithuanian and Latvian. Hungarian and Estonian languages are a part of the Uralic language group - more specifically, Finno-Ugric, which also includes Finnish. Romanian is a Latin language, and the language of the Roma is grouped with Hindu and Urdu, which are Middle Indic languages.
The Slavic languages themselves can be broken into more specific categories. The West Slavic languages comprise Polish, Czech, Slovak, Serbian, and Old Church Slavonic. Slovenian, Serbo-Croation, Bulgarian, and Macedonian are classified as South Slavic languages. And making up the East Slavic languages are Russian, Ukrainian, and Belorusian.
Read more about Eastern European languages and communication:
Origins of the Word Slav: The origins of the word "Slav" have been traced back to the word slovo, meaning "word."
Cyril, Methodius, and Cyrillic: Bulgaria was the first Eastern European nation to gain a written alphabet. Cyril and Methodius, two Byzantine monks, are thought to be instrumental in the development of the Cyrillic alphabet. Old Church Slavonic was the first Eastern European language to be written down. The Bible saw its first translations into Old Church Slavonic using a version of the Cyrillic alphabet.
History of Lithuanian Language: Scholars have concluded that Lithuanian language bears some resemblances to Sanskrit. Lithuanian has been so slow to develop, it is often used to study its mother language, Proto-Indo-European.
History of Latvian Language: Latvian language has progressed more rapidly than its more conservative sibling, Lithuanian. While similarities between the two Baltic languages exist, Lithuanians and Latvians cannot communicate with each other when speaking their native tongues.
History of Estonian Language: Estonian is the black sheep of the languages of the Baltic nations. It more closely resembles Finnish than it does Lithuanian or Latvian.
History of Hungarian Language: Hungarian, also known as Magyar, is in the same Finno-Ugric category as Estonian.
History of Polish Language: Polish language, a true Slavic language, developed out of the mingling of Slavic tribes of the region.
In some cases, the languages of Eastern Europe have struggled to survive. Many have undergone revivals while nationals sought to defy oppressors' forbiddance from speaking the language of their homelands. In other cases, a larger population abroad speaks their inherited language than speak it locally. As with all languages, the languages of Eastern Europe continue to develop, but strong patriotism arises out of personal knowledge about the language of one's people, and this has been an important factor during difficult, political times.