in English is:

bilingualism

Mutations

Soft:ddwyieithedd
Nasal:nwyieithedd
Aspirate:(no mutation)

Use

y dwyieithedd hwn
fy nwyieithedd i
dy ddwyieithedd di
ei ddwyieithedd ef/o
ei dwyieithedd hi
ein dwyieithedd ni
eich dwyieithedd chi
eu dwyieithedd nhw/hwy
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