ERD/Schema Diagram - FK "crowfoot"

Is there a way to “guess” at what type of connection should exist on a Schema Diagram to denote a FK based soley on the Schema data from the database?

Obviously is the Source field or Destination field is a PK… then one end of the line is not going to be “0 to ?” or “many to ?”

but there are
stewart06012008_3

From JUST the schema
I cant think of one