I know Swami Vivekananda gave a speech in Chicago 1893, I assume it was in English or was it translated to American audience. I am reading the complete works of Swami Vivekananda from Holybooks.com. If he educated himself in English, which institutions was he educated from?
Upon researching more about Swami Vivekananda, link provided by @SwamiVishwananda, I have come to understand that he is very well read in English also, could be a pundit in Bangla by default. Hence all his English speeches and writings are of his own.
Also this link provides more evidence of his schooling and university.
In 1879, Narendra passed matriculation and entered Presidency College, Calcutta. After one year, he joined the Scottish Church College, Calcutta and studied philosophy. He studied western logic, western philosophy and history of European nations. As he advanced in his studies, his thinking faculty developed. Doubts regarding existence of God started to arise in Narendra's mind. This made him associate with the Brahmo Samaj, an important religious movement of the time, led by Keshab Chandra Sen. But the Samaj's congregational prayers and devotional songs could not satisfy Narendra's zeal to realise God.
It appears to me that upper class family in India adopted to learn and educate themselves in English.