"My brother-in-law is a cook."
Translation:Svogeren min er kokk.
I'm really coming to appreciate how Esperanto does "in law." Just plug the affix bo~ in front of a family member's title. For example, Svogeren would be bofrato while sister in law is bofratino, etc.
Not that I'm advertising, but it's much less to remember, and it's spoiled me for things like this.