Skip to Main Content

SPAG: Spelling, Punctuation, and Grammar: Sentence Structure

Tips to improve and correct common errors in academic and formal writing.

Complete Sentences

More about complete sentences

Use complete sentences.
Eschew fragments.

This rule is not absolute, BUT

You can only use fragments if you have first proved to your readers that you know how to use complete sentences correctly.

If you don't know what eschew means, you should probably not use fragments yet.

To learn more, see:

Run-on, or Fused, Sentences

More about run-on sentences

Separate run-on, or fused, sentences, or join them correctly.

A run-on sentence is two sentences living together without benefit of proper punctuation.

They can be short or long.

Either way, it's a bad idea.

Length is not what determines a run-on sentence. You could write an entire book in one sentence; it's been done, but it's not a great idea, either.

To learn more, see:

Active voice

More about active voice

Use active voice unless you have a good reason not to.

In active voice something or someone performs an action or experiences a feeling.

  • Example: The salesperson closed the deal. She felt happy. (The person did something to the deal.)

The opposite is passive voice, where an action or feeling is experienced.

  • Example: The deal was closed. Happiness was felt. (The deal experienced the thrill of being closed? The salesperson or customer did something go it. We don't know who or what felt happy.)

Reasons to use active voice:

  • It's clearer for readers.
  • It creates stronger writing in most cases.
  • It is less wordy.
  • It focuses on the actor, not the receiver of action.

Reasons to use passive voice:

  • It can add variety.
  • It obscures blame or indicates uncertainty.
  • It focuses on the receiver of the action, which is sometimes important.


Active voice: The girl hit the ball out of the park.
Passive voice: The ball was hit out of the park by the girl.

Active voice: Nancy failed to submit the figures on time.
Passive voice: The figures were not submitted on time.

Active voice: Print and hand the report to me by Tuesday.
Passive voice: The report should be submitted on Tuesday.

To learn more, see: