“Jeff Campbell never knew very well these days what it was that was going on inside him. All he knew was, he was uneasy now always to be with Melanchta. All he knew was, that he was alway uneasy when he was with Melanchta, not the way he used to be from just not being very understanding, but now, because he never could be honest with her, because he was now always feeling her strong suffering, in her, but he knew now he was having a straight, good feeling with her, but she was so fast, and he was so slow to her; Jeff knew his right feeling never got a chance to show itself strong, to her.”
Stein, Gertrude, “Melanchta” in Three Lives, Dover Publication, 1994, p96.
After several paragraphs on the confused thoughts of Jeff Campbell, the repetition of the verb know is used to show how the character tries to assure his feelings to himself even though we can see that he’s still very confused and doesn’t know how to deal with it.