"I am a member of the Roman Catholic Church."

Translation: Dw i'n aelod o'r Eglwys Gatholig Rufeinig.

[AbunPang]

Do you have to use o here? Could you not say aelod Eglwys Gatholig Rufeinig?

[mizinamo]

Wouldn't that be "a member of a Roman Catholic Church" rather than "...of the..."?

Though I wonder whether aelod yr Eglwys.... would work.

Edit: On second thoughts, I expect aelod yr Eglwys... would be "the member of the..." based on how Welsh possession works.

[ibisc]

When something/someone is a part of something else the preposition o is usually used.

[AbunPang]

Ah I see, thank you!