A simple sentence is one complete thought.
A complete thought has a subject doing something.
The dog barked.
Josh rode a bicycle.
We ate pizza for dinner.
Each of these complete thoughts has a subject doing something.
dog barked
Josh rode
We ate
You might add extra words to give more information, like this:
The neighbor’s big dog barked all night long.
However, in this sentence, we still have only one thing happening: The dog is barking.
Here are some more simple sentences with extra information:
Josh rode his new red bicycle to school.
We are deep-dish pizza for lunch this afternoon.
Even though there are many words in the sentence, it’s still a simple sentence if we have one main idea – one thing happening.
A simple sentence must always end with a period. A period is “stop punctuation” – punctuation we use to show that we’ve come to the end of a thought.
A simple sentence has one main idea and one thing happening. Use a period to show the end of a thought in a simple sentence.