"They walk on the grass."
Translation:Eles caminham na grama.
grama and relva are both used. Grama is used in Brasil and Relva is the word generally used in Portugal
Relva is used in Portugal, where grama refers to grass more as a botanical entity.
I wrote - Eles andan na grama.
I received this message - You have a typo. Eles caminham na grama. LOL