What's a Compound/Complex sentence?

Question

Can someone explain to me what a compound/complex sentence is and give a few examples please? thanks!

Answer 1

A compound/complex sentence has 2 independent clauses and a dependent clause.  Independent clauses are groups of words that can stand alone as sentences.  Independent clauses have a subject and a verb and make sense outside of the original sentence.  Dependent clauses can't, so they are missing essential information and don't make sense if they were pulled out of the original sentence.  

Wikipedia explains and uses a few examples. http://en.wikipedia.org/wiki/Complex-com...

example:  

The cat lived in the backyard, but the dog, who knew he was superior, lived inside the house.

The cat lived in the backyard (makes sense alone, independent)

but the dog lived inside the house (makes sense alone, independent)

who knew he was superior (you don't know who it's referring to if it is pulled out of the original sentence.  It doesn't make sense. dependent)

Hope that helps!  

Answer 2

A clause is a structure that has both a subject and a predicate.  In the simplest case, that means a noun (or pronoun) and a verb.  Sometimes the predicate phrase can get quite involved, but a single subject/verb pair, no matter how involved, still constitutes just one clause.

A compound sentence has more than one independent clause.  A complex sentence has an independent clause and at least one dependent clause.  Compound/complex has features of both: either compound independent clauses with at least one subordinate clause, or compound subordinate clauses attached to at least one independent clause.

Simple sentence:  I was late for work this morning.

One subject (I) and one verb (was) and a bunch of other stuff in the predicate.  Therefore, one independent clause in the sentence.  

Compound sentence:  I was late for work this morning, and I might miss my deadline.

Two subjects (I and I) each with its own verb (was and might miss).  Two independent clauses joined by a coordinating conjunction (and).  

Complex sentence:  Because my wife didn't set the alarm, I was late for work this morning.

Two subjects (my wife and I), two verbs (did [not] set and was), and a subordinating conjunction marking one of the clauses as subordinate (because).  

Compound/complex sentence:  Because my wife didn't set the alarm, I was late for work this morning and I might miss my deadline.

After Sally met John, I never heard from her again and my life became much simpler.

My girlfriend is going to a concert and she won't be back until very late, so I have the place to myself for tonight.

I love you and you love me, so let's hang Barny from a tree.

I'll be at O'Mally's because I hate dancing but I love karaoke.

The idea (convoluted as it is) is this:  Complete sentences have at least one clause.  An independent clause can stand as a sentence by itself.  Just one clause is a simple sentence.  More than one clause, when neither clause depends on the other, is a compound sentence.  More than one clause, when one of the clauses does depend on the other, is a complex sentence.  And, a complex sentence where one of the types of clauses (dependent or independent) also happens to be compound, is compound/complex.

The trickiest part is learning when one thing "depends on" another grammatically.  You might think that my lateness depends on my wife's not setting the alarm.  However, as far as grammar is concerned,  the clause that starts with "because" is dependent.  Once that makes sense, counting dependent and independent clauses is easy.