Take a look at

http://cpearson.com/excel/duplicat.htm#ExtractingCommon

In article ,
Wilmarjr
wrote:

I am trying to do something that looks simple but I can't figure out.
I am trying to copy for a third column the names that match from the
first two columns. for example:

1º column 2º column
Nina john
john Ryan
smith Sherry
bob chuck
carlos bob
chuck sam
andrea

I would like to have a third column if john, chuck and bob's name.