More on Simple Sentences
Simple sentences are called 'simple' because they contain only one subject and one verb, or predicate. What's a predicate? A predicate is the main verb in a sentence and any additional components related to the subject's actions.
For example:
I will shop at the store this weekend.
In this sentence 'I' is the subject, and 'will shop' is the predicate. The verb 'shop' is helped by the auxiliary verb 'will,' and together they form the predicate.