ROME – Almost from the beginning of the Pope Francis era, foreign trips have captured the pontiff at both his best and worst. They showcase his tenderness and closeness to the people but also illustrate his stubborn, maverick nature, at times kicking up a storm of dust and leaving his press crew to clean up the aftermath.

Never is this dynamic clearer than when the pope has the chance to hit the road in his native Spanish. By virtue of language alone, his travels to Spanish-language countries tend to bring out a more charismatic Francis, closer to the people, more spontaneous and, unbridled by language gaps or prepared texts, able to express himself more freely.

In other words, letting Francis speak Spanish is a bit like giving him a strong dose of steroids.

When Francis arrives in Panama for World Youth Day on Wednesday, it will be his 26th trip outside Italy. Looking back at those outings, there’s a notable stylistic difference when he’s in Latin America – not only is he more spontaneous, going off-the-cuff more than usual, but he tends to use stronger, more poignant language that is clearer and richer in symbolism, and he isn’t afraid to do so even in more formal settings.

For example, after landing in Quito, Ecuador during his second visit to South America as pope, in his opening speech at the airport, Francis issued a stinging rebuke to authorities that vulnerable minorities “are the debt that Latin America still has [to pay].”

In fact, even outside Latin America, Spanish seems to loosen the pope’s tongue.

While visiting Nairobi, Kenya in 2015, Francis tossed aside his prepared speech during an audience with priests and religious, telling them in Spanish with an English-language interpreter that God hates indifference, and that when a consecrated person forgets Christ, “they have fallen in an ugly sin, a sin that disgusts God, that makes God vomit.”

Most of the pope’s off-the-cuff moments come in his speeches to priests and youth. By now it’s almost customary for Francis to put aside his prepared remarks and “speak from the heart” during his audiences with young people, and priests and religious, and while he can be repetitive, his message is typically adapted to his audience, often drawing either applause or tears – and sometimes both.

Speaking in Morelia, Mexico, one of the country’s most violent cities, in 2016, he said young people cannot have hope unless they learn to value themselves and start to believe that “not all is lost.”

“The biggest threat to hope is when you feel that you do not matter to anybody or that you have been left aside. The biggest threat to hope is when you feel that, either being present or absent, you make no difference,” he said in the off-the-cuff speech, and, eliciting tears from many of the 50,000 youth present, said that the drug trade, the lack of work and the death of friends and family due to violence all contribute to the feeling of hopelessness, which finds its remedy in Christ.

He also tends to drop words only known to Spanish-speakers, even terms that most Spanish-speakers wouldn’t know unless they come from Buenos Aires, such as urging Argentine youth to hacen lio, or to “wreak havoc” on the streets during his 2013 visit to Rio de Janiero for World Youth Day.

(The pope’s vivid language, by the way, is also employed in interviews in Spanish. Just one example is how during an interview in 2016, he said journalists who only report scandals suffer from coprophilia – a psychological condition in which the person is obsessed with feces.)

International trips are also when Francis’s maverick instincts go into over-drive, leading him to break the rules and strike out on his own. In a 2015 trip to Sri Lanka he made a surprise visit to a Buddhist temple, and while in the Philippines he made an unannounced appearance in a home housing former street kids in Manila.

However, the pope’s spontaneity doesn’t always play in his favor, since he can also sometimes come off as irascible, stubborn, and closed.

Perhaps the best-known example came during his visit to Chile last January, when he said victims of the country’s most notorious abuser, ex-Father Fernando Karadima, were guilty of “calumny” for accusing Bishop Juan Barros, the former bishop of Osorno whom Francis had consistently backed despite widespread protest, of covering up Karadima’s crimes.

Francis made the off-hand comments to a local television network on his last day in Chile, saying he had no “proof” that Barros was guilty, and essentially boiling down the complaints – which had been consistent since 2015 – to a matter of ideology, rather than fact.

The incident lead to a PR disaster for Francis, who back-peddled during the flight to Rome, saying he did not have any evidence of Barros’ guilt but would accept any if it were presented. When it came out that a letter from a victim detailing Barros’ involvement with Karadima and knowledge of the former priest’s abuses had been given to him in 2015, Francis then launched an investigation and eventually received the resignations of every bishop in the country.

As the pope prepares to travel to Panama this week, it’s likely that the same dynamic can be expected – a pope of surprises who refuses to play by the rules, as well as the tender-hearted pastor the world first fell for in 2013.