Переклад слова «certain» з англійської на українську мову

For adreadful instant, Penny was certain she could not.
A thief named Camar, who stole a certain talisman.
He listened attentively and with a certain eagerness.
No less a matter than the sharing of a certain secret occupied his mind.
A certain clouding of the iris began to show, premonitory of color-deposit.