- to trade, do business comercian con los países árabes they trade o/or do business with the Arab countries comercia con su cuerpo [eufemístico/euphemistic] she sells her body comerciar
enalgo to trade o/or deal insth comerciaban en pieles they were trading o/or dealing in skins
Here is a selection of useful words and phrases you will need in real-life situations while you're visiting Spain and other Spanish-speaking countries...
Mossos d'Esquadra is the name of the police force of the Catalan autonomous region. It has a wide range of responsibilities but the Guardia Civil and Policía Nacional also operate in Catalonia.