THE PLOT OF THE STORY

To my mind the author used description of the place where actions take place because he wanted to introduce the reader with this streets cheap
apartments. 

"These "places" make strange angles and curves. One Street crosses itself a time or two. An artist once discovered a valuable possibility in this street."

EXPOSITION: 

The action begins when Sue and Johnsy shared a flat on the third store of the old house. The author describes that this girls have things in common. 

"At the top of a squatty, three-story brick Sue and Johnsy had their studio. "Johnsy" was familiar for Joanna. One was from Maine; the other from California. They had met at the table d'hte of an Eighth Street "Delmonico's," and found their tastes in art, chicory salad and bishop sleeves so congenial that the joint studio resulted."

But in the month of November Johnsy got a pneumonia.  

RISING EVENTS:

Johnsy was thought that she would die when the last ivy leaf fell. 

"Five what, dear? Tell your Sudie."

"Leaves. On the ivy vine. When the last one falls I must go, too. I've known that for three days. Didn't the doctor tell you?"

Then Sue told this words to their neighbor Berhman their problem. 

CLIMAX: 

Johnsy learnt a lesson from the last leaf. She wanted to correct her mistake. She wanted to live.

"I've been a bad girl, Sudie," said Johnsy. "Something has made that last leaf stay there to show me how wicked I was. It is a sin to want to die. You may bring a me a little broth now, and some milk with a little port in it, and - no; bring me a hand-mirror first, and then pack some pillows about me, and I will sit up and watch you cook."

And hour later she said:

"Sudie, some day I hope to paint the Bay of Naples."

FALLING ACTIONS:

The doctor said to Sue that her fried would recover.But Mr. Berhman got a pneumonia and there was no hope for him. 

"Even chances," said the doctor, taking Sue's thin, shaking hand in his. "With good nursing you'll win." And now I must see another case I have downstairs. Behrman, his name is - some kind of an artist, I believe. Pneumonia, too. He is an old, weak man, and the attack is acute. There is no hope for him; but he goes to the hospital to-day to be made more comfortable."

RESOLUTION:

Sue said to Johnsy that Mr. Berhman sacrificed his life for the sake of her.

 "I have something to tell you, white mouse," she said. "Mr. Behrman died of pneumonia to-day in the hospital. He was ill only two days. The janitor found him the morning of the first day in his room downstairs helpless with pain. His shoes and clothing were wet through and icy cold. They couldn't imagine where he had been on such a dreadful night. And then they found a lantern, still lighted, and a ladder that had been dragged from its place, and some scattered brushes, and a palette with green and yellow colors mixed on it, and - look out the window, dear, at the last ivy leaf on the wall. Didn't you wonder why it never fluttered or moved when the wind blew? Ah, darling, it's Behrman's masterpiece - he painted it there the night that the last leaf fell."

The author used dialogues. He wanted to make this story easier to the reader. He used  not a lot description.