Translation guide
The global war from 1914 to 1918, referred to in Japanese primarily as 第一次世界大戦 (Daiichiji Sekai Taisen).
Referring to World War I as a historical period or event.
In casual conversation or writing, 第一次大戦 (Daiichiji Taisen) is often used instead of the full 第一次世界大戦.
The standard, formal term for World War I. Used in history, education, and media.
World War I began in 1914.
The causes of World War I are complex.
A common abbreviation of 第一次世界大戦, used in both spoken and written contexts.
The peace treaty of World War I was signed at Versailles.
The English abbreviation is sometimes used in Japanese texts, especially in informal or online contexts, but it is not standard.
I'm studying the history of WWI.