Sometimes sentences are too complex or too long to read because no punctuation or conjunction is used to connect ideas. When two clauses that could be independent sentences are joined that way, you’ve written a run-on sentence.

Consider the following run-on sentence:

Heavy wind and rain struck the area Tuesday, many businesses and homes were out of power.

The sentence really consists of two sentences that could stand alone: Heavy wind and rain struck the area Tuesday and many businesses and homes were out of power.

One simple solution is to simply separate those parts into their own sentences by correctly punctuating them with a period:

Heavy wind and rain struck the area Tuesday. Many businesses and homes were out of power.

Instead of using a period, though, you could keep the sentences connected with a semicolon:

Heavy wind and rain struck the area Tuesday; many businesses and homes were out of power.

You also might use a conjunction (and, but, or, so) with a comma before it to connect the two parts of the sentence:

Heavy wind and rain struck the area Tuesday, and many businesses and homes were out of power.

Which option you go with depends on how you wish to relate the ideas (A stronger connection is suggested when using a semicolon or a conjunction.), the audience’s reading level (Younger readers will better understand shorter sentences.), and maintaining some variety in syntax (If the previous sentence used a conjunction to combine two sentences, you probably want to split this sentence into two.).