Tente ingressar entre o cliente e a tabela de teste como:
SELECT c.forename, COUNT(c.forname)
FROM Client c INNER JOIN Test t
ON c.clientNo = t.clientNo
WHERE c.forename = 'Jim'
AND t.status = 'PASS'
GROUP BY c.forname
SELECT c.forename, COUNT(c.forname)
FROM Client c INNER JOIN Test t
ON c.clientNo = t.clientNo
WHERE c.forename = 'Jim'
AND t.status = 'PASS'
GROUP BY c.forname
