[11] In addition, there is some disagreement whether Standard Latgalian and Kursenieki, which are mutually intelligible with Latvian,[12] should be considered varieties or separate languages.

The Latvian and Lithuanian languages have retained many features of the nominal morphology of Proto-Indo-European, though their phonology and verbal morphology show many innovations (in other words, forms that did not exist in Proto-Indo-European),[14] with Latvian being considerably more innovative than Lithuanian.

This process of consolidation started in the 13th century after the Livonian Crusade and forced christianization, which formed a unified political, economic, and religious space in Medieval Livonia.

[18] The oldest known examples of written Latvian are from a 1530 translation of a hymn made by Nikolaus Ramm [lv], a German pastor in Riga.

[19] The oldest preserved book in Latvian is a 1585 Catholic catechism of Petrus Canisius currently located at the Uppsala University Library.

The Lutheran pastor Gotthard Friedrich Stender was a founder of Latvian secular literature.

[23] After the death of Alexander III at the end of the 19th century, Latvian nationalist movements re-emerged.

After the Soviet occupation of Latvia, the policy of Russification greatly affected the Latvian language.

Massive immigration from the Russian SFSR, Ukrainian SSR, Byelorussian SSR, and other republics of the Soviet Union followed, primarily as a result of Stalin's plan to integrate Latvia and the other Baltic republics into the Soviet Union through colonization.

Minority schools are available for Russian, Yiddish, Polish, Lithuanian, Ukrainian, Belarusian, Estonian and Roma languages.

Latvian is taught as a second language in the initial stages too, as is officially declared, to encourage proficiency in that language, aiming at avoiding alienation from the Latvian-speaking linguistic majority and for the sake of facilitating academic and professional achievements.

Since the mid-1990s, the government may pay a student's tuition in public universities only provided that the instruction is in Latvian.

Since 2004, the state mandates Latvian as the language of instruction in public secondary schools (Form 10–12) for at least 60% of class work (previously, a broad system of education in Russian existed).

Observance of the law is monitored by the Latvian State Language Center run by the Ministry of Justice.

The Terminology Commission suggested eira or eirs, with their Latvianized and declinable ending, would be a better term for euro than the widely used eiro, while European Central Bank insisted that the original name euro be used in all languages.

Latvian dialects and their varieties should not be confused with the Livonian, Curonian, Semigallian and Selonian languages.

There are three syllable intonations in some parts of Vidzeme variety of the Central dialect, extended, broken and falling.

The immigrant and minority population in Latvia is 700,000 people: Russians, Belarusians, Ukrainians, Poles, and others.

[32] The increased adoption of Latvian by minorities was brought about by its status as the country's only official language and other changes in the society after the fall of the Soviet Union that mostly shifted linguistic focus away from Russian.

As an example, in 2007, universities and colleges for the first time received applications from prospective students who had a bilingual secondary education in schools for minorities.

Latvian grammar represents a classic Indo-European (Baltic) system with well developed inflection and derivation.

Today, the Latvian standard orthography employs 33 characters: The modern standard Latvian alphabet uses 22 unmodified letters of the Latin alphabet (all except ⟨q, w, x, y⟩, which are usually replaced by ⟨k(v)⟩, ⟨v⟩, ⟨ks⟩, and ⟨i/j⟩ respectively in loanwords and even in foreign names, though they may appear in certain specialized terms such as status quo; "W" can be found in older texts, "Y" can be found in the Latgalian language/dialect).

The letters ⟨ģ, ķ, ļ, ņ⟩, written with a comma placed underneath (or above them for lowercase g), which indicate palatalized versions of ⟨g, k, l, n⟩ representing the sounds [ɟ], [c], [ʎ] and [ɲ].

Latvian orthography also contains nine digraphs, which are written ⟨ai, au, ei, ie, iu, ui, oi, dz, dž⟩.

[33] Nowadays standard QWERTY or the US keyboards are used for writing in Latvian; diacritics are entered by using a dead key (usually ', occasionally ~).

In the 1990s, lack of software support of diacritics caused an unofficial style of orthography, often called translits, to emerge for use in situations when the user is unable to access Latvian diacritic marks (e-mail, newsgroups, web user forums, chat, SMS etc.).

In this style, diacritics are replaced by digraphs – a doubled letter indicates a long vowel (as in Finnish and Estonian); a following j indicates palatalisation of consonants, i.e., a cedilla; and the postalveolars Š, Č and Ž are written with h replacing the háček, as in English.

Latvian has six vowels, with length as distinctive feature: /ɔ ɔː/, and the diphthongs involving it other than /uɔ/, are confined to loanwords.

During the period of Livonia, many Middle Low German words such as amats (profession), dambis (dam), būvēt (to build) and bikses (trousers) were borrowed into Latvian, while the period of Swedish Livonia brought loanwords like skurstenis (chimney) from Swedish.

[38] Loanwords from other Baltic language include ķermenis (body) from Old Prussian, as well as veikals (store) and paģiras (hangover) from Lithuanian.