DELAY, DELAY, DELAY
There's a pretty standard ending to any rom-com: love, marriage, and a honeymoon in Niagara Falls (or Albany.)
So the point of the plot is less to get you there (you know where you're going to end up anyway) and more to spin out events and more events so you have a full hour and a half of screen time before you do get there.
And His Girl Friday is chock-filled.
Few films delay as thoroughly and inventively as His Girl Friday. The very first scene, in which Hildy and Walter spar, is one long interrupted conversation. Hildy wants to tell Walter that she's getting remarried, but she keeps getting cut off—often by discussions about being interrupted. (And yet Walter manages to keep it suave. Because Cary Grant.)
They banter back and forth about how Walter hired a plane to skywriter during their divorce, delaying the proceedings—and they reminisce about how their honeymoon was put off by a mine disaster:
HILDY: Instead of two weeks in Atlantic City with my bridegroom, I spent two weeks in a mine with John Kruptzky.
When Hildy finally does tell Walter the news, he immediately begins plotting to keep her from going through with it.
WALTER: Is there any way we can stop the 4:00 train to Albany?
DUFFY: We could dynamite it.
WALTER: Could we?
Walter has to think up something trickier than dynamiting the train, but he manages. First he gets Hildy to cover the execution, then he sets Bruce up to be put in jail over and over—and then he even kidnaps Hildy's mother-in-law.
By the end of the film, Hildy finally breaks down and cries, maybe because she realizes Walter loves her, but maybe just because she's so exhausted with the hour-and-a-half runaround.
His Girl Friday takes a lot of time and a lot of words to get you to your eventual happily-ever-after destination. But, as they say, the journey is the destination.
Though the film is almost bewilderingly clever in inventing ways to slow things down, it's pretty straightforward in the way it presents the story. You're almost always following Hildy—although there are occasional jumps to follow other parts of the story (like Walter's machinations, or the Mayor's sneaky scheme) when necessary.
Hawks is a no-nonsense old Hollywood director; he doesn't mess around with chronology or complicated point of view. He tells you the dang story from beginning to end—with a few witty detours along the way, of course.