Sentences: clarification of terms
The terms simple, compound and complex when related to sentence types implies differing degrees of sophistication, and also differing lengths, but this is a misconception. Simple sentences can be short and sophisticated, because they are used for emphasis or to create suspense, for example. Or they can be long, with considerable sophisticated elaboration to provide detail. Likewise complex sentences can be short or they can be long sentences, expressing sophisticated arguments and relationships.
Simple: a sentence containing one clause
§ I found him in the garage on a Sunday afternoon.
§ The winter was ending.
§ Near the peak of the mountain, in the shadow of the summit, I stood in silence, with the thunder of the wind in my ears and a cold chill on my cheeks.
Compound: a sentence with two or more clauses joined by a co-ordinating conjunction
§ The Dursleys had a small son called Dudley and in their opinion there was no finer boy anywhere.
§ We thought a little longer, and in the end we simply called her Joy.
§ We stood and wept.
Complex: a sentence with a main clause and one or more subordinate clauses
§ It was the day after we moved into Falconer Road.
§ Mr Dursley was the director of a firm called Grunnings, which made drills.
§ I lie because I am scared.