From Duolingo:

Possessive (“Genitive case”):

• [het] [Owen] – [hat] of [Owen]; Owen’s Hat
• [pannas] [Owen] – [parsnips] of [Owen]; Owen’s parsnips
• [cath] [Olwen] – [cat] of [Owen]; Olwen’s cat
• [tŷ mawr] [Siôn a Sioned] – [Siôn and Sioned]’s [large house]
• [siop fach] [Gruff] – [Gruff]’s [little shop]