Originally Answered: Complex and Compound Sentence help?
Basically, in a compound sentence, both clauses are independent--that is, they each have a subject and a verb, and (this is the important distinction) each IC could stand alone as a complete sentence, expressing a complete thought.
In a complex sentence, one clause is independent, and the other clause is dependent - it too has a subject and a verb, but canNOT stand alone as a complete sentence, expressing a complete thought.
So, go through each sentence with two highlighters - different colors. Locate the independent clause. Highlight it. Locate the dependent clause, if there is one. Use a different color to highlight it.
If each clause in the sentences above expresses a complete thought and could stand alone as a sentence, then you have a compound sentence. Each IC in a compound sentence is equally important as far as the information's significance to readers--at least, that's the way it's supposed to be (grin). The term for this compound sentence is COORDINATION - which is how you can look it up in a grammar handbook.
If one clause in each sentence above is IC, and the other is DC, then your sentence is complex. That construction is called SUBORDINATION - which is how you look it up in a grammar handbook. The less-important-to-the-reader information is carried in the dependent clause.
A couple more things about these ideas:
Compound sentences need a comma before the coordinating conjunction (if there is one.) Look at #4 -
Okonkwo thinks farming is his top priority (Independent clause)
so (coordinating conjunction)
...he can support his family with food (Independent clause)
Consequently, compound sentence. If, however, you use a coordinating conjunction and don't put in the comma before it, you have a run-on sentence. Usage is changing; in your lifetime, that comma may get thrown out of the grammar rulebook, but in formal academic writing you need it.
You can remember the coordinating conjunctions by the memory-device FANBOYS.