There are two criteria worth mentioning: (a) "is it funny?" and (b) "is it Doctor Who?"
Erey weyddiimeed oo ka kooban 'maxaa'iyo 'ay', labo xaaladood ayaana loo adeegsadaa, sida: a) "Waa maxay?"; b) "Maxay doonaysaa ama doonayaan?"