Insurance and provision in Portuguese

The seventeenth entry is o pagamento semestral, and the adjective hides a number that most English readers have never noticed inside it. « Semester » looks as though it opens with « semi- », half, and the way we use the word encourages the reading: a semester is one of the two halves of an academic year. The half is a coincidence. Semestris is sex, six, welded to mensis, month — six-monthly, and nothing more — with the x lost in front of the m. Once that is visible the Portuguese family reads itself without a dictionary: semestral is every six months, trimestral every three, bimestral every two, and o semestre is a stretch of six months whatever a university chooses to do with it. So O pagamento semestral vence em junho announces a payment made twice a year, which we would call half-yearly. A reader who hears « semi- » in the word gets that one right by accident and trimestral wrong for certain, because three months is not half of anything here. The rule that never fails is to count the months rather than the halves.