If you are unable to go to the polling station on polling day you can apply to have a proxy vote: this is where you appoint somebody to vote for you.
Os na allwch fynd i'r orsaf bleidleisio ar ddiwrnod yr etholiad, gallwch wneud cais i gael pleidlais drwy ddirprwy: dyma lle rydych chi'n penodi rhywun i bleidleisio ar eich rhan.