Simple sentences are okay, but compound sentences and complex sentences are not. The sentences make sense, but do not seem skillfully written. There is some variety in sentence beginnings, length, and structure. The reader has to hunt for clues to see how one sentence should flow into the next. Some parts of the text sound good when read aloud, others are choppy and sound funny when read aloud.
Most sentences are incomplete or run together.
The sentences do not sound natural. The text is not at all like a person would talk. The reader may have to pause or read the sentences again to understand what is meant. There is no variety in sentence beginnings, length, or structure. There are several fragments or most of the sentences run together with no connections.