Subquery problems

Hello,

I'm trying to build some subquery, and it don't works like I want.

I try the following query :

select distinct pseudo, (select count(ref) from questions where
questions.refpseudo=pseudos.refold) as xxx from pseudos;

That query work well on MSAccess, but I have the following error on
postgres :

ERROR:  parser: parse error at or near "select"

I must maybe using an other method. I'm want to optain in a simple query
to list some name of my table pseudos and to see the number of occurency
in the table questions.

Thank. Jérôme Knöbl, Switzerland