*O Petros exi enan dhaskalo stin Veria , ala dhen exi mia dhaskala stin Katerini .
the Petros has a.M teacher.M in.the Veria but not has one.F (teacher.F) in.the Katerini
(intended) ‘Petros has a male teacher in Veria, but he doesn’t have one (female teacher) in Katerini.