a terrible teacher but really nice guy,easy to talk to.
Best Teacher Ever! Great Classes, great craic, never a dull moment util he retired!
WHAT A LEDGEND BEST FORM TEACHER IN THE ENTIRE SCHOOL!!
Fantastic teacher with a brilliant mind, terrible lack of discipline though
1986-92 Dreadful teacher, couldn't keep control, learnt virtually nothing !
Very nice man but is completely wasted teaching maths. Not able to control a class unfortunately. No wonder I failed badly...
Mr Costello is lik da best teacher ever i lov him so much maths wud suck without him (",)
How can we get any work done if he won't stop starting a conversation with his favorite students? 25 mins of chatting and 20 mins of class!
what a truely genuine man,i had him for a bit of jc,thanks Brian,i really mean it,great teacher!
Sound man, just a pity he refuses to take control of his class. Sure some people dont want to work, but they make it difficult for the rest of us :(
i think hes a sound man i havent come across any faults yet
Good teacher but really needs to keep control on his class. Sometimes very hard to get work done simply because he wont tell certain people to shutup
Probably the most uninteresting teacher ever. He can't even start a class without having a long chat with his favorite students. A very poor quality teacher!