Compound sentences are two simple sentences, or independent clauses, joined together to make a longer sentence. If you find your writing is filled with short sentences, creating little variety in your paragraphs, practice combining sentences that are closely related. Compound sentences, used judiciously, can improve the flow of your writing and help your audience better understand what you are trying to communicate.

Add a coordinating conjunction to join two simple sentences. A coordinating conjunction shows how and why ideas are connected. The most commonly used are and, but, for, or, nor, so and yet. Place a comma before the coordinating conjunction when making a compound sentence. For example, combining these two sentences requires a conjunction to help hold them together:

Walking is good exercise.
You need to stretch your muscles before you go.

Add the coordinating conjunction "but" along with a comma before it, to create a compound sentence:

Walking is good exercise, but you need to stretch your muscles before you go.

Use a semi-colon to form a compound sentence. While a coordinating conjunction, such as "and" or "so" could be used when ideas are closely linked, a semi-colon may help a sentence flow better:

My dad is addicted to junk food; he eats it every day.

Make a compound sentence by using a conjunctive adverb such as also, besides, finally, later, then, however and instead. Conjunctive adverbs have a semi-colon before them, and a comma after. For example:

I have a lot to do today; also, I have a lot on my mind.

Use a transitional expression to form a compound sentence. Some examples of transitional expressions are after all, for example, in other words and as a result. As with conjunctive adverbs, place a semi-colon before the transitional expression:

Compound sentences can improve the flow of your writing; for example, this sentence is a compound sentence.

Memorize frequently used coordinating conjunctions, conjunctive adverbs and transitional expressions.

Practice writing compound sentences over and over again. As with most things, repetition will help you to remember how to write a compound sentence.

Use the correct words and punctuation to combine simple sentences, or you may inadvertently create run-on sentences or comma splices.