A simple sentence is a sentence, for example: I played a game. And a compound sentence is I played game and I ate my food.
compound
nothing
complex
A simple subject and simple predicate are the two main parts of each sentence. A simple subject is the common pronoun, noun, or proper noun that tells who the sentence is about. A simple predicate is the verb in the sentence that acts on the subject.
Stop and think! - It is a simple sentences This is an imperative sentence, there is no subject just two verbs.
Compound simple
This sentence is a simple sentence because it contains only one independent clause.
This sentence is a simple sentence.
compound
Simple sentence, compound sentence, complex sentence and compound complex sentence.
compound sentence, simple sentence, and complex sentence
nothing
Yes, it is possible to use a compound subject in a simple sentence. A compound subject consists of two or more subjects that are connected by a coordinating conjunction such as "and" or "or." For example, "Sara and Emma went to the park" is a simple sentence with a compound subject "Sara and Emma."
simple
simple, compound, complex, compound-complex
If you are talking about predicates it is simple. If you are talking about subjects it is compound.
Simple.