Simple sentences are independent clauses.
They contain a subject and a predicate.
Rule 1: Simple sentences can be very short, consisting of only one word (a noun) for the subject and one word (a verb) for the predicate. The noun is called the simple subject, and the verb is the simple predicate.
Example:
Richardo laughed.
Rule 2: Simple sentences can be long, although they still consist of one subject (a noun and modifiers) and one predicate (a verb and other elements). The noun is called the simple subject, and the verb is the simple predicate.
Example:
The tall, well-dressed boy with the curly blond hair laughed uproariously at his best friend’s suggestion.
Rule 3: Simple sentences can have a compound subject or a compound predicate.
Examples:
Simon and Garfunkel recorded an album that year. (compound subject)
America’s best known novelists, journalists, and editors attended a conference in New York last week. (compound subject)
Marianne sang, danced, and played the violin with equal competence, passion, and enthusiasm. (compound predicate)
The brilliant student received top marks on all of her final exams, graduated with honors, and was interviewed for a junior faculty postion. (compound predicate)