Albert Einstein primarily spoke German as it was his native language. Born in the Kingdom of Württemberg in the German Empire in 1879, he grew up in a German-speaking environment. Additionally, as he moved through different phases of his life, he learned and used other languages as well.
In his later years, after relocating to the United States in 1933, Einstein became fluent in English and conducted much of his professional and public life in this language. Despite the change in location and language, he never forgot his roots and continued to speak German throughout his life.
Einstein’s multilingual capabilities allowed him to communicate effectively with a diverse range of scientists and intellectuals around the world. His ability to speak multiple languages is a reflection of the cosmopolitan nature of his life and work.