For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Luckily for us Shmoopers, D.H. Lawrence makes a tidy division between Part I and Part II of this book at the end of Chapter 6, and this division corresponds neatly with the end of Act I. Act I of the book lays out the Morel family dynamics, giving special attention to the relationship between Gertrude Morel and her husband Walter, as well as their four children.
The book focuses mainly on William in this act. William's the eldest son, and he looks like he's going to grow up to be quite the hot shot. Unfortunately, he dies, and we're left with Paul as our new main character as we head into Act II.
Act II
As Paul grows up, Mrs. Morel takes all the love and ambition she once focused on William and throws it onto Paul with a suffocating intensity. Squirm. Paul gets himself a nice little factory job and starts finding some success with his landscape paintings. He also meets a nice young girl named Miriam Leivers, who's very pretty, but also a little bit clingy and emo.
Paul decides that he really likes Miriam, but doesn't want to be her boyfriend. Mrs. Morel doesn't like Miriam at all, thinking that the girl is going to suck the life out of her son and make him average. But she's probably just jealous.
As Paul gets older, he decides that he attracted to an older (married) woman named Clara Dawes, and starts sleeping with her. He spends so much time with her, in fact, that he doesn't even notice the monster tumor that has started growing out of his mother's abdomen.
The tumor eventually kills Mrs. Morel, and, like Act I, Act II of the book ends with the death of a Morel.
Act III
Without his mommy around to tell him what to do, Paul loses his sense of direction in life. He spends most of his time knocking around town and doing solo pub crawls every night of the week. He breaks things off with Clara Dawes, who gets back together with her estranged husband.
One night, Paul sees Miriam leaving church, and asks her to come hang out with him. The two of them talk about getting married, but quickly realize that neither one is willing to take an active role and say "Marry me."
The scene ends in stalemate (of the stalest kind), and Miriam leaves. Paul thinks about killing himself, but then heroically decides that life isn't so bad. Yay.