Simple Subject and Simple Predicate

What is the simple subject/simple predicate in this sentence? I believe the butter is fake.

I/believe

What is the simple subject/simple predicate in this sentence? I occasionally sing in the shower.

I/sing

What is the simple subject/simple predicate in this sentence? Mr. Kerr tells the students what a great job they are doing.

Mr. Kerr/tells

What is the simple subject/simple predicate in this sentence? The purple cat eats the yellow mouse.

cat/eats

What is the simple subject/simple predicate in this sentence? The black dog runs around the pond in the winter.

dog/runs

What is the simple subject/simple predicate in this sentence? The pretty girl walks into the building.

girl/walks

What is the simple subject/simple predicate in this sentence? Sometimes, the grandmother of my mom writes stories of her past.

grandmother/writes

What is the simple subject/simple predicate in this sentence? Mom is tall.

mom/is

What is the simple subject/simple predicate in this sentence? The little sister of Elvis plays catch in Missouri.

sister/plays

What is the simple subject/simple predicate in this sentence? Mr. Batman's son eats crayons.

son/eats

What is the simple subject/simple predicate in this sentence? The teacher and student learn together

teacher, student/learn

Simple predicate is the same thing as the.....

verb

What is the simple subject/simple predicate in this sentence? Basketball was my favorite sport.

Basketball/was