What was Queen Victorias mother tongue?

Answer 1

Victoria and Albert spoke to each other in German. However this does not indicate

that German was her mother tongue. She was fluent in English, of course but German

the language of her home life.

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It is safe to say that Queen Victoria's mother tongue was German. She was taught only German by her mother Princess Victoria of Saxe-Coburg-Saalfeld (Mary Louise Victoria; 17 August 1786 - 16 March 1861), until she was three years old. She was then taught English and French as well, so that she effectively grew up trilingually. It is said that while her command of English was good, it was not perfect.

Answer 2

More than likely her mother tongue was German. Her mother was German and Victoria did not learn how to speak English until she was three years old.

[Another opinion]

Most historians of the period agree that Victoria was allowed to speak only English at home (see, for example, Elizabeth Longford 'Victoria R I'). Her German-speaking mother - Princess Victoria - was very ambitious for her young daughter, and knew that a teenager who spoke only German (or even mainly German) would be isolated at the Court of Saint James. The young Victoria would also have needed to speak English to her 'comptroller' John Conroy (who was rumoured to be involved with Victoria's mother), as well as to all the servants and visitors.

Victoria had a step-brother and a step-sister who both spoke German, so she would have been familiar with the languages: but it seems unlikely that an arch schemer like the Princess Victoria would have missed a chance to get her royal-line daughter a place in the English establishment.