I have been trying to work out a solution to the following problem without any success.
Are there any experts out there that can help?

List the name of each city in the city table that is not shown as the capital of a country in the country table
Write an SQL query to satisfy this request using a left outer join

The significant columns in the country table are
name -- name of the country
capital - capital of that country.

The significant columns in the city table are
name -- name of the city
country --- the country where that city is located

select a.Name from city a left outer join Country b on a.Name = b.Capital where b.Name is null