WarcraftLoreTracker — the whole Warcraft story, in order

Timeline

Warcraft Encyclopedia: Thalassian

Web article · 2006 · A World of War(craft) · 25 after the Dark Portal

Web article2006

Warcraft Encyclopedia: Thalassian is an official Warcraft web article, published in 2006. In the timeline it belongs to 25 A.D.P, in A World of War(craft) (24 A.D.P to 29 A.D.P).

The article

Also known as: High Elven (nonstandard)

Thalassian is the primary language of blood elves and high elves. It has both written and spoken equivalents. Individuals who are unfamiliar with the language's proper name may refer to it as High Elven.

Like Nazja, Thalassian is derived from the Darnassian language. Hence, Thalassian is closely related to Darnassian, and there is some overlap between the two languages. Further Darnassian utterances may therefore have been preserved in modern Thalassian, in addition to those that are specified below.

So far, linguistic scholars have opted to err on the side of caution in documenting Darnassian terms and phrases that are also considered part of the Thalassian language. Certainly this issue, however delicate, merits further research. Nevertheless, addressing a high elf or blood elf with a Darnassian-specific word or phrase can be considered offensive or at the very least rather foolish, and so the speaker must handle the situation with care.

References

The information could be retrieved from http://www.wow-europe.com/en/info/encyclopedia/576.xml.