Can any one please tell me the query for the given scenario:

I have a very bad knowledge with SQL queries,so kindly help me:

I have two tables "Advertisement" and "responses".
Advertisement table fields are: AdID(unique),title,username
responses table fields are:AdID(which is the same value in Advertisement table),responses.(it may have any number odf responses for the same Ad id)

Now i need a single query in which i should get the Adid,Title and the count of number of responses to the Adid: