Portuguese Prime Minister Antonio Costa attends a ceremony marking the World Portuguese Language Day at Centro Cultural de Belem in Lisbon, Portugal, on May 5, 2021. (Photo: Xinhua)

Guests attend a ceremony marking the World Portuguese Language Day at Centro Cultural de Belem in Lisbon, Portugal, on May 5, 2021. (Photo: Xinhua)

A video message from Portuguese President Marcelo Rebelo de Sousa is shown at a ceremony marking the World Portuguese Language Day at Centro Cultural de Belem in Lisbon, Portugal, on May 5, 2021. (Photo: Xinhua)