De Quental began to write poetry at an early age, chiefly though not entirely devoting himself to the sonnet. As a child, he took French lessons under António Feliciano de Castilho, a leading figure of the Portuguese Romantic movement, who resided in Ponta Delgada. Despite their relationship, De Quental would later criticize Castilho and other Romantic poets, sparking a divisive conflict. De Quental was seven when he was enrolled at Liçeu Açoriano, a private school where he received English lessons from Mr. Rendall, a renowned prospector on the island. In August 1852, de Quental moved with his mother to the Portuguese capital, where he studied at Colégio do Pórtico, whose headmaster was his old tutor Castilho. When the institution closed, de Quental returned to Ponta Delgada in 1853. On writing to his old headmaster, he said: