Analysis of Chi È?

When for a buonamano
Cometh, at break of day,
Knock at the terzo piano,
A little voice answers, Chi è?
``I, the facchino, awaiting
The bounty of cara lei.''
She droppeth a paul through the grating,
And silently steals away.

When, with a long low mumble
Of lips that appear to pray,
There cometh a knock-so humble-
The little voice answers, Chi è?
``I, the poor monk.'' Just a little
She opens, but nought doth say;
Gives him baiocchi or victual,
And silently steals away.

But when, as the shadows longer
Stretch half athwart the way,
There cometh a knock, much stronger,
The little voice answers, Chi è?
And when I answer, Io!
No bolts nor bars delay;
But, with the wild whisper, Ah Dio!
We kiss, and we steal away.