Expression is a synonym of Discourse. Discourse is a synonym of Talk. Begin is a type of Talk. 
one thing you do when you Working is Thinking. Working is related to Smell. Smell is a different concept from Hear. 
Expression <--Synonym--> Discourse <--Synonym--> Talk <--IsA-- Begin 
Thinking <--HasSubevent-- Working <--RelatedTo--> Smell <--DistinctFrom--> Hear 