Samantha and Mady collected seashells then cleaned them. Samantha and Mady are the subjects. The compound predicate that is collected and cleaned is telling you what they both did.
Compound subjects have more than one subject....and the same with predicates
Susan and her dog love to run and splash in the waves at the beach.
hobbyists enjoy and earn from there hobby...
secret
Learn about Probability of Compound Events with Number Cubes
How to Solve Compound Inequalities
How to Solve Compound Inequalities Using AND Operator
How to Graph Compound Inequalities