How to combine multiple rows of a table to a single row in sql server and join to another table

Question

How can i merge the rows of a teachers qualification from its table to a single row and join it to another so i can search for a given condition to know if a teacher possesses the given degree/certification. Or is there a better approach other than the one i am trying to use? Thanks in advance. Second image.

SELECT 
    StaffTable.TeacherType,     
    StaffTable.StaffID,
    TeacherQualificationsTable.YearOfGraduation,
    TeacherQualificationsTable.SubjectMajorsCombination,
    STUFF((SELECT 
               ', ' + [DegreeObtained] 
           FROM 
               TeacherQualificationsTable FOR XML PATH('')),1,1,'') AS [DegreeObtained]
    FROM     
        StaffTable 
    INNER JOIN
        TeacherQualificationsTable 
    ON 
        StaffTable.StaffID = TeacherQualificationsTable.StaffID 
    INNER JOIN
        AppointmentChronologyTable ON StaffTable.StaffID = AppointmentChronologyTable.StaffID
    WHERE  
        (StaffTable.TeacherType = @TeacherType) 
        AND (StaffTable.StaffStatus = @StaffStatus) 
        AND DegreeObtained NOT CONTAINS ('B.Ed (Bachelor of Education)' , 'M.Ed (Master of Education)', 'G.D.E (Graduate Diploma in Education)')
    ORDER BY 
        StaffTable.LastName, 
        StaffTable.FirstName, 
        StaffTable.MiddleName

I have a staffTable and a staffQualificationsTable (which will have multiple qualification entries for any given staff). Am required to check if some staff have some given qualifications eg 'B.Ed (Bachelor of Education)' , 'M.Ed (Master of Education)', 'G.D.E (Graduate Diploma in Education)' and return all the staff without it so they will be called to tender theirs or laid off. Please, i hope this is clearer.