Collocations for keen - adj.

appear, be, feel, look, seem, sound | remain

awfully, desperately, especially, extremely, frightfully, mad (informal), more than, particularly, really, terribly, very
He''s mad keen on football. | She''s a very keen gardener.

not at all, not overly, not too
The banks were not at all keen to lend to somebody who actually seemed to need money.

fairly, pretty, quite, rather | always
She was always keen to hear the local gossip.

obviously | naturally, understandably
She was naturally keen to make a good impression.

for
They were desperately keen for information.

on
Sally''s quite keen on the idea.

as keen as mustard
(= very keen)