One of the primary techniques Llewellyn uses to reveal his characters and develop them is describing their actions and circumstances. Through this, we learn their inner character traits, their thoughts, their motives, and their feelings. An example of this is the first paragraphs of Chapter One. Beginning in medias res, Huw Morgan is preparing for his secret departure from the Valley.
He tells us his action: he is going to pack his "two shirts with [his] other socks and ... best suit." Now we know his background is an economically modest one. He tells us the immediate circumstance: he is using his mother's "little blue cloth" and doesn't want to go get his basket from Mrs. Tom Harries. Now we know he is leaving in silence, probably in sorrow. He tells us another circumstance: the blue cloth is too valuable to be used for packing, but he has "promised it a good wash and iron." Now we know how he feels about his mother and that he was raised in a careful and tidy household.
Another example in the same chapter is the introduction of Huw's father. His actions are described. He left the farm. He came to town. He whistled down the street. He saw a servant girl pull the curtains. He stopped whistling. He fell in love. Now we know his father is light-hearted, quick to love, perhaps impractical, and optimistic. We also have a foreshadowing of upcoming difficulty because of the possibility of impracticality.
My father met [my mother] when she was sixteen ... he came whistling ... he saw my mother drawing curtains .... He stopped whistling ... they looked and fell in love.
Llewellyn's emphasis on actions and circumstances is part of what creates the mood of melancholy in the story, and it does a thorough job of revealing and developing characters and their mental and emotional states and processes.
I have stood outside ... seeing in my mind all the men coming up black with dust, and laughing ... walking bent-backed because the street is steep ....
He reveals all the caracters through the eyes of Huw Morgan the narrator