Complex sentence: He could not even understand what his brother meant when he said things made him shudder, and when his father asked him what he would like to learn, to support himself, he said he would like to learn to shudder.
Split into simpler sentences: He could not even understand what his brother meant when he said that things made him shudder. When his father asked him what he would like to learn, to support himself, he said he would like to learn to shudder.