I have an example for you.

I wrote an English song entitled "I'm at the Mercy of Your Smile", both lyrics and melody. A friend of mine translated the lyrics to French. The song title is "Je suis envoutee par ton sourire" and he used my melody from the English song, "Mercy". He and I are now co-writers of the French version. On that one we split any royalties and the writer credit. I still own the melody royalties, but he now has the lyric royalties. Both songs are on a CD out in two days. In the olden days, if a 45 had been released and the songs were Side A and B respectively, the royalty split would be 25% for Pierre and 75% for me. Hope that's clear.