In 1511, Aguilar was shipwrecked near the Yucatán Peninsula. Along with Gonzalo Guerrero, he began living with the Chetumal Mayans and learned their language. When Hernán Cortés and his men gained access to the Mayans through the slave Malinalli, they found Aguilar and Guerrero.
Aguilar was able to communicate with Malinalli through the Mayan language. On meeting the Nahuatl-speaking Tlaxcalans and Aztecs, Malinalli translated Nahuatl to Mayan for Aguilar, who would then translate Mayan to Spanish for Cortés and his men.