Translation:It rained more on Monday than on Tuesday.
I think that "It rained more Monday than Tuesday" should also be accepted as a valid translation of this sentence.
I agree with Nick without at least the first "on" the sentence reads as if Mondays and Tuesdays are the things that are raining... which you could probably use as a metaphor since nobody likes Monday. Think of it as saying, "it rained more cats than dogs. "
Would it be possible to also correct the drop down definition for "che"? And can "che" really be used for such disparate things: 'that'', ''what'', ''and'' and ''than''? A lot of work for one little word. ;-)
"Than" is what's used for comparing two things, "then" is used to express a story/process' next step. "First, I entered the dark hallway. Then, I turned on the light. It was darker here, than in the room with the large windows."