Context: CREATE TABLE countrylanguage (CountryCode VARCHAR, Language VARCHAR, IsOfficial VARCHAR); CREATE TABLE country (Name VARCHAR, Code VARCHAR)
Question: What are the names of nations where both English and French are official languages?
Answer: SELECT T1.Name FROM country AS T1 JOIN countrylanguage AS T2 ON T1.Code = T2.CountryCode WHERE T2.Language = "English" AND T2.IsOfficial = "T" INTERSECT SELECT T1.Name FROM country AS T1 JOIN countrylanguage AS T2 ON T1.Code = T2.CountryCode WHERE T2.Language = "French" AND T2.IsOfficial = "T"