Irish Down Syndrome Ambassador Michael Gannon wants to break down prejudices after Pontiff chat.Getty Images

Pope Francis arrived in the US yesterday afternoon, touching down in Washington D.C. at the start of his six-day tour.

He was greeted at Joint Base Andrews by President Obama and Vice President Biden.

Because he is not as fluent in English as he is in other languages, his translator, Monsignor Mark Miles, was by his side and will be with him for the duration of the trip.

The knowledge of English that Pope Francis does have goes back to the time he spent living in Dublin in 1980.

Thirty-five years ago, back when Pope Francis was known as Jorge Mario Bergoglio, he spent three months living and studying English at the Jesuit Center in Dublin’s Milltown Institute.

READ MORE: Little known facts about Ireland - Pope Francis and Winston Churchill both lived in Dublin

Francis, then 43, had just wrapped up seven years as the head of the Jesuit order in his native Argentina. The country was in turmoil at the time with the military junta and the Dirty War.

As the Irish Independent reported before Pope Francis’ first Urbi et Orbi message in 2013, the July 1980 edition of the Jesuit bulletin, the Irish Province News, noted that among the "constant stream of visitors who found hospitality with us we may mention Fr Jorge Bergoglio, ex Provincial of Argentina and Rector of our Theologate in Buenos Aires."

Young Pope Francis, when he was a seminarian (before his time in Dublin).

Young Pope Francis, when he was a seminarian (before his time in Dublin).

During his time in Dublin, Francis attended classes, went for walks around the Dublin 6 neighborhood, chatted with other students and seminarians, and spent time studying and reflecting in his room.

On January 21, an old ledger belonging to the school shows, he visited the bursar to borrow £14 for language tapes.

"He was on a sabbatical when he came to Ireland so it was an ideal place for him,” Rev Fergus O'Donoghue SJ told the Irish Independent.

READ MORE: Pope Francis' ten commandments for living a happy life 

“He had left Argentina after a traumatic time and would have been recovering from that. There are long walks right through the grounds of Gonzaga College and Milltown Park which he would have enjoyed.

"Milltown was a community in transition at the time. It had been built as a house for young Jesuits to study in and there would have been a lot of lay students, men and woman, coming and going, studying theology. He would have appreciated that the lifestyle was very simple."

The Milltown Institute, Sandford Road, Dublin.

The Milltown Institute, Sandford Road, Dublin.

While Francis is still known for adhering to that simple lifestyle, eschewing some of the papal luxuries preferred by his predecessors, his US tour will be anything but simple. Today he will visit the White House and say mass in Washington DC, where he will also address Congress on – a first for any pope. 

On Thursday he heads to New York, where he will address the United Nations and celebrate vespers at St. Patrick's Cathedral. On Friday he will tour the city, stopping, among other places, in Central Park and at the 9/11 memorial, and saying mass at Madison Square Garden. 

On Saturday and Sunday he will be in Philadelphia, where he will say mass and attend the tri-annual World Meeting of Families, for which he will also celebrate an open air mass on Sunday.