Married couples were the focus of Pope Francis' second "balcony talk" in Poland on Thursday, receiving from him three words he has often said are key to a successful marriage.

"Sometimes they ask me how to make it so that the family always goes forward and overcomes difficulties," the Pope said July 28, adding that when this happens, "I suggest to them to practice three words."

Speaking in his native Spanish, he said these words "can help to live married life because in married life there are difficulties," adding that marriage is something we have to take care of, "because it's forever."

The three words are "permission, thanks, and forgiveness."

Pope Francis was speaking at the end of his first full day in Poland, where he is spending July 27-31 for World Youth Day. Each night when he comes back to Krakow after the day's activities, Francis is set to appear on the balcony of the local archbishop's palace to address youth gathered below.

The tradition was begun by St. John Paul II, who spoke to youth from the balcony every time he visited his homeland as Pope – had been Krakow's archbishop from 1964 until his 1978 election as Bishop of Rome. It was continued by Benedict XVI when he visited Poland in 2006, and is now being carried on by Francis.

In yesterday's encounter Francis recounted the moving story of a young student who rediscovered his faith after leaving school to volunteer for WYD in designing the banners that currently line Krakow's streets, but passed away from cancer before the event arrived. He praised the young man's faith, and encouraged the youth gathered to spread the joy of their faith in Christ throughout the city.

In his speech from the balcony Thursday, he focused on married couples, explaining that whenever he sees a young couple is getting married or has just done so, "I tell them they are the ones who have courage, because it's not easy to form a family."

"It's not easy to make a life commitment, it takes courage, and I congratulate them because they have courage," he said, noting that the three words "permission, thanks, and forgiveness" come in handy every day of married life.

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On the topic of permission, the Pope said to "always ask your spouse, the wife to the husband and the husband to the wife, 'what do you think, what do you think if we do this?'" rather than just "running over" the other without getting their opinion.

He also stressed the need to be grateful, "because it's the spouses who confer the sacrament of marriage, one to the other. And this sacramental relationship is maintained with this sentiment of gratitude, of thanks."

The third word, he noted, is forgiveness, which is "a very hard word to say." In marriage, mistakes are always made, he said, noting that the important thing is to know how recognize one's mistakes and ask for forgiveness.

This "does a lot of good," Francis continued, urging families and engaged couples to "remember these three words, which will help you to a lot in married life: permission, thank you, and forgiveness."

In marriage "there are always problems or discussions. It's habitual and it happens that the husband and wife argue, raise their voice, fight," he said, noting that "somethings the plates fly."

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"But don't panic when this happens," he said, and advised couples to never finish a day without making peace, "because the cold war the day after is very dangerous."

A simple gesture is enough to make this peace, he said, tapping his face twice, adding that "when there is love, a gesture fixes everything."

Pope Francis then invited the youth to pray for all the families who were present, for those who are married and those who are engaged, and led the crowd in praying a Hail Mary, each country in their own language.