Question

Ellos _____ en el mar.

a) nadé

b) nadamos

c) nadaron

d) nadó

Answer 1

It’s C because yo-nadé, tu,usted-nadaste, el/ella-nadó, nosotros-nadamos, ellos/uds-nadaron

Answer 2

it is not a,d,b. I have never heard it end with Ron however. c would be the only possible one