Yes, George I was indeed able to speak English. Not particularly well, mind you, but also not nearly as incapably as popular history portrays. In fact, he even opened his first Parliament in English:
George is reported, when seated on the throne, to have uttered the words following; but, notwithstanding all the drilling to which he submitted, it must have been a very awkward, if not a ludicrous exhibition: "My Lords and Gentlemen, I have ordered my Lord Chancellor to declare to you, in my name, the causes of calling this parliament."
Campbell, JCB. The Lives of the Lord Chancellors and Keepers of the Great Seal of England. Lea and Blanchard, 1847.
While this could have simply been a memorised speech, Ragnhild Hatton's landmark biography supplies several more contemporary attestations of the king's ability to understand the English language:
- The chancellor, Earl Cowper, reports speaking English to the king and receiving answers in French
- An English sentence recorded by Lady Cowper: "What did they go away for? It was their own faults [sic]", which the Hatton considers to be a direct quote of the king
- Mehemet, George's Turkish servant, increasingly used untranslated English in the king's private accounts
- The king's arrangement of, and attendance at, English plays, as well as an expressed desire to see a particular actor perform
Some of these are more persuasive than others, but taken as a whole, it becomes apparent that George obviously had at least a working knowledge of English, if not immediately then certainly a few years into his reign. In fact, within a decade of his assumption of the British throne, we have documentary evidence of George conducting British government business in English:
In the Public Record Office there is a memorandum of 1723 in English by Townshend on which George has written in his own hand: 'I agree with you in everything contain'd in this letter, and desire you to communicate your opinion either to the Duke of Newcastle or H. Wapole, that the instruction to the ambassadors may be sent according to your opinion'. GR.
Hatton, Ragnhild. George I. Yale University Press, 2001.