Proper Sindarin form of an invented Quenya name "Márafinwë"?

Chociewitka #2788

Hi,

for an invented son of Finrod and Amarië born in Aman named "Márafinwë" (which was "Mariëfinwë" originally, but I have been convinced "Márafinwë" suits here better)

would the proper Sinarin rendition be "Finmaer" or "Finvaer"? I do struggle with the concept of Sindarin lenition. I assume also the Telerin rendition would be something akin to"Findamáro"?

Gwilithiel #2789

Finvaer would be correct. The combination “nm” cannot occur in Sindarin, and “m” is always lenited to “v” when it is the starting letter of the second word in a compound name.

Chociewitka #2790

Thank you very much, it is a great help!