you are likely to find Light in/at/on Porch. you are likely to find Dog in/at/on Porch. Dog is related to Parent. Parent is related to Boy. 
Begin is related to Finish. Dress is a type of Finish. Dress is related to Wedding. 
Light --AtLocation--> Porch <--AtLocation-- Dog <--RelatedTo--> Parent <--RelatedTo--> Boy 
Begin <--RelatedTo--> Finish <--IsA-- Dress <--RelatedTo--> Wedding 