I was reading an article about types of sentences. It seemed very easy to understand simple and compounds at first, but there is something wrong with the examples! Please read the following sentence:
Mary and Samantha arrived at the bus station early but waited until noon for the bus.
As you can see there is a coordinative conjunction "but" in this sentence and I belive that this is compound. But in the written text it was classified as a simple sentence! The writer mentioned that "arrived" and "waited" is a compound verb, while the whole sentence is considered to be a simple sentence.