🔤 Grammar Guide: Common Sentence Errors
Fixing fragments, run-ons, comma splices, and other sentence problems
Introduction | Common Sentence Errors | Nouns | Pronouns | Verbs | Modifiers | Prepositions | Conjunctions | Glossary and Resources
A sentence usually needs at least a subject and a verb. In plain language: Someone or something does or is something.
Most sentence errors happen when a sentence is incomplete, when too many complete thoughts are joined incorrectly, or when the main parts of the sentence do not fit together.
Long sentences are not automatically wrong. Short sentences are not automatically clear. The real question is whether readers can follow who or what the sentence is about, what is happening, and how the sentence parts connect.
For more guidance on making sentences easier to read, see Garbl’s Plain Language Writing Guide, especially its section on sentences. This grammar guide focuses on correctness and sentence structure; the plain language guide focuses more broadly on clarity, readability, and reader-friendly choices.
Incomplete sentences or missing subjects and verbs
Readers need to know who or what the sentence is about and what is happening. A sentence can become confusing when the subject or verb is missing, buried, or unclear.
A sentence should express a complete thought. It can be incomplete because it lacks a subject, lacks a verb, or starts a thought without finishing it.
A word group may name something without saying what happened or what is true about it:
Problem:
A beautiful purple and white rhododendron.
Better:
A beautiful purple and white rhododendron bloomed beside the porch.
A word group may start a thought without finishing it:
Problem:
Because the meeting lasted three hours.
Better:
Because the meeting lasted three hours, the vote was delayed.
The meeting lasted three hours.
A word group may leave out who acted or what happened:
Problem:
After reviewing the proposal and hearing from residents.
Better:
After reviewing the proposal and hearing from residents, the council delayed the vote.
The council reviewed the proposal, heard from residents, and delayed the vote.
The corrected sentences make clear who acted and what happened.
Incomplete sentences are often called fragments. They can sometimes work for emphasis, rhythm, or voice. But they should be intentional and clear. In formal, official, technical, or instructional writing, complete sentences are usually safer.
Run-on sentences
A run-on sentence joins two or more complete thoughts without the right punctuation or connecting words.
Problem:
The meeting lasted three hours the vote was delayed.
Better:
The meeting lasted three hours, so the vote was delayed.
The meeting lasted three hours. The vote was delayed.
Run-on sentences force readers to figure out where one thought ends and the next begins.
Comma splices
A comma splice joins two complete sentences with only a comma.
Problem:
The bill passed the House, the Senate has not voted.
Better:
The bill passed the House, but the Senate has not voted.
The bill passed the House. The Senate has not voted.
The bill passed the House; the Senate has not voted.
A comma alone is not strong enough to join two complete sentences.
For more guidance on commas, semicolons, and other punctuation marks used to join or separate sentence parts, see the punctuation entries in Garbl’s Editorial Style and Usage Guide.
Introduction | Common Sentence Errors | Nouns | Pronouns | Verbs | Modifiers | Prepositions | Conjunctions | Glossary and Resources