Could this literally be understood as 'Sixty are the members of the Assembly'? And therefore why 'oes.....' isn't used in the Welsh, even though it's very tempting from the English!?
Where does the "there are" come in, i just translated it (incorrectly) as "sixty members of the assembly".
Mae is the verb here. In this pattern - one concerning the existence of something - it is translated as 'There is/are...':
- Mae teigr yn y gegin - There's a tiger in the kitchen
- Mae dau fwnci ar gefn y teigr - There are two monkeys on the tiger's back