"The butterfly is on the book."
Translation:Fluturele e pe carte.
When there's the combination "preposition + single noun", you don't use the definite article:
El e pe carte.
But if this noun has an adjective, the definite article is necessary:
El e pe cartea albastră.
Salutări din Brazilia!
It says "Fluturele se află pe carte." is correct too. What does "se află" mean? Don't think I had that in a lesson yet.
It is roughly translated as "is found". "The butterfly is found on the book". In Spanish, one would say "se halla", "La mariposa se halla en el libro".