Polish (język polski, polszczyzna) is a West Slavic language spoken primarily in Poland and is the native language of the Poles. It belongs to the Lechitic subgroup of the West Slavic languages. Polish is the official language of Poland, but it is also used throughout the world by Polish minorities in other countries. It is one of the official languages of the European Union. Its written standard is the Polish alphabet, which has 9 additions to the letters of the basic Latin script (ą, ć, ę, ł, ń, ó, ś, ź, ż). Polish is closely related to Kashubian, Silesian, Upper Sorbian, Lower Sorbian, Czech and Slovak.

Although the Austrian, German and Russian administrations exerted much pressure on the Polish nation (during the 19th and early 20th centuries) following the Partitions of Poland, which resulted in attempts to suppress the Polish language, a rich literature has regardless developed over the centuries and the language currently has the largest number of speakers of the West Slavic group. It is also the second most widely spoken Slavic language, after Russian and just ahead of Ukrainian.

In history, Polish is known to be an important language, both diplomatically and academically in Central and Eastern Europe. Today, Polish is spoken by over 38.5 million people as their first language in Poland. It is also spoken as a second language in western parts of Belarus, Lithuania and Ukraine, as well as northern parts of the Czech Republic and Slovakia. Because of the emigration from Poland during different time periods, most notably after World War II, millions of Polish speakers can be found in countries such as Australia, Brazil, Canada, the United Kingdom, Ireland, and the United States. There are 55 million Polish language speakers around the world.

Japanese (日本語 Nihongo) is an East Asian language spoken by about 125 million speakers, primarily in Japan, where it is the national language. It is a member of the Japonic (or Japanese-Ryukyuan) language family, whose relation to other language groups, particularly to Korean and the suggested Altaic language family, is debated.

Little is known of the language's prehistory, or when it first appeared in Japan. Chinese documents from the 3rd century recorded a few Japanese words, but substantial texts did not appear until the 8th century. During the Heian period (794–1185), Chinese had considerable influence on the vocabulary and phonology of Old Japanese. Late Middle Japanese (1185–1600) saw changes in features that brought it closer to the modern language, as well as the first appearance of European loanwords. The standard dialect moved from the Kansai region to the Edo (modern Tokyo) region in the Early Modern Japanese period (early 17th century–mid-19th century). Following the end in 1853 of Japan's self-imposed isolation, the flow of loanwords from European languages increased significantly. English loanwords in particular have become frequent, and Japanese words from English roots have proliferated.

Japanese is an agglutinative, mora-timed language with simple phonotactics, a pure vowel system, phonemic vowel and consonant length, and a lexically significant pitch-accent. Word order is normally subject–object–verb with particles marking the grammatical function of words, and sentence structure is topic–comment. Sentence-final particles are used to add emotional or emphatic impact, or make questions. Nouns have no grammatical number or gender, and there are no articles. Verbs are conjugated, primarily for tense and voice, but not person. Japanese equivalents of adjectives are also conjugated. Japanese has a complex system of honorifics with verb forms and vocabulary to indicate the relative status of the speaker, the listener, and persons mentioned.

Japanese has no genetic relationship with Chinese, but it makes extensive use of Chinese characters, or kanji (漢字), in its writing system, and a large portion of its vocabulary is borrowed from Chinese. Along with kanji, the Japanese writing system primarily uses two syllabic (or moraic) scripts, hiragana (ひらがな or 平仮名) and katakana (カタカナ or 片仮名). Latin script is used in a limited fashion, such as for imported acronyms, and the numeral system uses mostly Arabic numerals alongside traditional Chinese numerals.

Korean (한국어/조선말, see below) is the official language of both Koreas: the Republic of Korea and the Democratic People's Republic of Korea, with different official forms used in each nation-state. It is also one of the two official languages in the Yanbian Korean Autonomous Prefecture and Changbai Korean Autonomous County of the People's Republic of China. Approximately 80 million people worldwide speak Korean.

Korean has a few extinct relatives, which together with Korean itself form the Koreanic language family. Despite this, historical and modern linguists classify Korean as a language isolate; however, the classification of the Jeju language as a distinct language necessarily implies that Korean is not an isolate, but a member of a small family. The idea that Korean belongs to the controversial Altaic language family or to the Dravido-Korean family has been largely discredited, particularly with the modern academic consensus debunking the Altaic language group entirely. There is still debate on whether Korean and Japanese are related languages. The Korean language is agglutinative in its morphology and SOV in its syntax.

Russian (ру́сский язы́к, russkiy yazik) is an East Slavic language and an official language in Russia, Belarus, Kazakhstan, Kyrgyzstan and many minor or unrecognised territories. It is an unofficial but widely spoken language in Ukraine and Latvia, and to a lesser extent, the other countries that were once constituent republics of the Soviet Union and former participants of the Eastern Bloc. Russian belongs to the family of Indo-European languages and is one of the four living members of the East Slavic languages. Written examples of Old East Slavonic are attested from the 10th century and beyond.

It is the most geographically widespread language of Eurasia and the most widely spoken of the Slavic languages. It is also the largest native language in Europe, with 144 million native speakers in Russia, Ukraine and Belarus. Russian is the eighth most spoken language in the world by number of native speakers and the seventh by total number of speakers. The language is one of the six official languages of the United Nations.

Russian distinguishes between consonant phonemes with palatal secondary articulation and those without, the so-called soft and hard sounds. This distinction is found between pairs of almost all consonants and is one of the most distinguishing features of the language. Another important aspect is the reduction of unstressed vowels. Stress, which is unpredictable, is not normally indicated orthographically though an optional acute accent (знак ударения, znak udareniya) may be used to mark stress, such as to distinguish between homographic words, for example замо́к (zamok, meaning a lock) and за́мок (zamok, meaning a castle), or to indicate the proper pronunciation of uncommon words or names.

Portuguese (português or, in full, língua portuguesa) is a Romance language and the sole official language of Portugal, Brazil, Cape Verde, Guinea-Bissau, Mozambique, Angola, and São Tomé and Príncipe. It also has co-official language status in East Timor, Equatorial Guinea and Macau. As the result of expansion during colonial times, a cultural presence of Portuguese and Portuguese creole speakers are also found in Goa, Daman and Diu in India; in Batticaloa on the east coast of Sri Lanka; in the Indonesian island of Flores; and in Malacca in Malaysia.

Portuguese is part of the Ibero-Romance group that evolved from several dialects of Vulgar Latin in the medieval Kingdom of Galicia, and has kept some Celtic phonology. With approximately 215 to 220 million native speakers and 260 million total speakers, Portuguese is usually listed as the sixth most natively spoken language in the world, the third-most spoken European language in the world in terms of native speakers, and a major language of the Southern Hemisphere. It is also the most spoken language in South America and the second-most spoken in Latin America after Spanish, and is an official language of the European Union, Mercosul, OAS, ECOWAS and the African Union.

Spanish author Miguel de Cervantes once called Portuguese "the sweet and gracious language" and Spanish playwright Lope de Vega referred to it as "sweet", while the Brazilian writer Olavo Bilac poetically described it as a última flor do Lácio, inculta e bela (the last flower of Latium, rustic and beautiful). Portuguese is also termed "the language of Camões", after one of the greatest literary figures in the Portuguese language, Luís Vaz de Camões.

In March 2006, the Museum of the Portuguese Language, an interactive museum about the Portuguese language, was founded in São Paulo, Brazil, the city with the greatest number of Portuguese language speakers in the world. The museum is the first of its kind in the world.  In 2015 the museum was destroyed in a fire, but there are plans to reconstruct it.