Complex sentences

Compound sentences contain a coordinating conjunction (FANBOYS).

I will have a large pizza , for I'm starving.

Complex sentences contain a subordinating conjunction (other conjunctions than FANBOYS).

I will have a large pizza because I'm starving.

Because I'm starving, I'll have a pizza.

1. I will have a pizza, for I'm starving.

The sentence is compound as we used a coordinating conjunction (for).

We also used a comma before the conjunction.

2. I will have a pizza because I'm starving.

The sentence is complex as we used a subordinating conjunction (because).

But we didn't use a comma before the conjunction.

3. Because I'm starving, I'll have a pizza.

The sentence is complex as we used a subordinating conjunction (because).

We used a comma in the middle of the sentence to seperate the two clauses.