a) Independent clause
All sentences need at least one independent clause to be made whole. An example of a complex sentence is: While he was sleeping, I did the laundry. "I did the laundry" is an independent clause because it is a complete sentence on it's own with the subject (I) and the verb (did). The subordinate clause is "While he was sleeping". This clause begins with a subordinating conjunction (While) which causes the rest to feel incomplete when it is read alone "While he was sleeping...". While he was sleeping ___what?
A compound sentence is when two sentences are combined using a coordinating conjunction such as and, for, nor, but, yet, so. I did the laundry and I cooked dinner. Here there are two complete sentences "I did the laundry", "I cooked dinner" joined together with "and". A subject is who or what the sentence is about. A prepositional phrase tells the reader where one noun is in relation to another. The bird is on the branch. "On the branch" is a prepositional phrase that tells you where the bird is.