As of about six months ago, the state of the art in this field is that you would, for instance, go up to the following psychologist with fabulous hair, and you'd say, "Steve, you're an expert on the irregular verbs.
Fa com sis mesos, el més novedós en aquest camp era que, posem per cas, hom aniria al psicòleg amb cabells fabulosos i li preguntaria, "Steve, tu que ets un expert en verbs irregulars.