Simple Sentence
Sentence type by structure depends on the number and relationship of clauses. A simple sentence contains one main clause; adding another coordinated main clause makes the structure compound, while subordination creates a complex relationship.
A simple sentence has one main or independent clause. It can still contain long phrases, compound subjects or objects, modifiers, and other internal complexity, so “simple” describes clause structure rather than length or sophistication.
Key details
Important caveats
Boundary
Do not confuse “simple sentence” with “easy sentence” or with sentence purpose categories such as declarative or interrogative.
Further guidance
Contrast
A second coordinated main clause changes the structure; dependent phrases alone do not.
Diagnostic
Count main clauses, not words. If there is one main clause, the sentence is structurally simple even when the clause contains many phrases or modifiers.
Worked Example
“The experienced editor in the corner reviewed the long report after lunch” is still a simple sentence because it contains one main clause.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Sentences (opens in a new tab)Cambridge University Press · Cambridge defines a simple sentence structurally as a sentence with only one main clause, contrasting it with compound and complex sentence structures.
- Sentence Punctuation Patterns (opens in a new tab)Purdue Online Writing Lab · Purdue uses independent-clause patterns to explain complete sentences and how independent clauses are joined, giving a practical writing boundary beyond definition alone.