0 to listen to someone's private conversation without them knowing: --
He was eavesdropping on our conversation.
1 to listen secretly to someone’s private conversation --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Можем да го завършим стъпка по стъпка, колкото и дълъг да е пътят и не може да бъде завършен, колкото и кратък да е пътят, ако дори не маркирате отпечатъка си.