I would say it like this I am Portuguese: 私はポルトガル人です (Watashi wa porutogarujin desu) I can speak Portuguese: ポルトガル語を話すことができます (Porutogarugo wo hanasukoto ga dekimasu) Portugal: ポルトガル (Porutogaru)

Watashi wa porutogaro jin desu. (I am Portuguese) Porutogaru go o hanashimasu. (I speak Portuguese) Porutogaru go o hanasu ga dekimasu. (I can speak Portuguese). Porotugaro (Portugal)