by Craig Shrives

What Is Tautology? (with Examples)

Tautology is the needless repetition of a single concept. For example:
  • He left at 3 am in the morning. wrong cross
  • (As "am" means "in the morning," the phrase "3 am in the morning" is a tautology. It expresses a single concept twice.)
This tautology can be corrected by removing one of the repeats.
  • He left at 3 am in the morning. correct tick
  • He left at 3 am in the morning. correct tick

Table of Contents

  • Easy Examples of Tautology
  • Some Harder Examples of Tautology
  • Real-Life Examples of Tautology
  • Video Lesson
  • Why Tautology Is Important
  • Printable Test
tautology examples
In most tautologies, the concept is repeated because a word is inherent in another. For example:
  • Unmarried bachelors tend to buy fancy cars. wrong cross
  • (In this example, the word "unmarried" is inherent in the word "bachelor," which means an unmarried man.)
This tautology can only be corrected by removing the word "unmarried."
  • Unmarried Bachelors tend to buy fancy cars. correct tick
  • Unmarried bachelors tend to buy fancy cars. wrong cross
The adjective from tautology is "tautological." As tautological expressions include redundant words, they are usually considered writing errors.

Formal Definition

Tautology: the use of two words or phrases that express the same meaning, in a way that is unnecessary and usually unintentional.
Cambridge Dictionary

Easy Examples of Tautology

Here are some examples of tautology. In each example, the tautological expression is shaded.
  • At that moment in time, the stars dimmed. wrong cross
  • (It is always a moment in time. The concept of time is inherent in the word "moment.")
  • This is a new innovation. wrong cross
  • (Innovations are always new. The concept of new is inherent in "innovation.")
  • The vote was totally unanimous. wrong cross
  • (The word "totally" doesn't add anything. "Totally" is inherent in "unanimous.")
  • He was in a three-way love triangle. wrong cross
  • (The word "three-way" doesn't add anything. It is inherent in "triangle.")

Some Harder Examples of Tautology

Sometimes, tautologies are harder to spot.
  • The reason is because he left during the dinner. wrong cross
  • (The word "because" doesn't add anything. It means "for the reason that.")
  • He was the reason why I left the job.wrong cross
  • (This example can be corrected by removing "the reason" or "why." They do the same job. "Why" means "for what reason." )
  • In our assessment, we think he is alive. wrong cross
  • ("In our assessment" and "we think" do the same job.)
Let's get technical for a second. In the examples below, quotation marks are used to denote "so-called"; therefore, the use of the word "so-called" is needless repetition.
  • He placed the chicken on the so-called "clean" surface. wrong cross
  • His so-called "mates" left him in the tree. wrong cross
Technically, there is no need for the word "so-called" in these two examples because that's what the quotation marks mean.

Real-Life Examples of Tautology

  • Many people's commute back and forth to work requires them to spend hours behind the wheel each day. wrong cross
  • (The words "back and forth" don't add anything.)
  • That's one of the great advantages of age...you can throw temper tantrums, and nobody minds. (Author James Lee Burke) wrong cross
  • (The word "temper" doesn't add anything.)
On occasion though, a tautological phrase reads better than the non-tautological version or gives the emphasis sought by the author.
  • I asked the question, "Will I ever perform again?" (Musician Brian Harvey)
  • (The words "the question" could be removed, but the result would be less empathic.)
  • Everyone is the sum total of past experiences. A character doesn't just spring to life at age thirty. (Writer Kelley Armstrong)
  • (The words "total" and "past" could be removed, but "sum total" and "past experiences" are set terms.)
  • Of course, everybody's thinking evolves over time. (Ethiopian politician Meles Zenawi)
  • (The words "over time" could be removed, but the emphasis on time would be lost.)
Here is a video summarizing this lesson on tautology.

Are you a visual learner? Do you prefer video to text? Here is a list of all our grammar videos.

Spotting tautology is useful for eliminating redundant words, which will not only reduce your word count but also portray you as a clear thinker. Here are some tautological terms that could be shortened safely (i.e., with no loss of meaning):
  • Armed gunman
  • Attach together
  • Depreciate in value
  • Warn in advance
Be careful though. Sometimes, a tautological term work will work better for you than the non-tautological version.
  • I need to ask the question.
  • We evolve over time.
Sometimes, you have to think whether something really is a tautology.

Example 1:

  • She died of a fatal dose of heroin.
Argument For: You don't need the word "fatal."
Argument Against: She might have died from a non-fatal dose, i.e., one that wouldn't kill most people.

Example 2:

  • Present a short summary.
Argument For: Summaries are always short.
Argument Against: Er, no they're not.

Example 3:

  • Enter your PIN number in the ATM machine.
Argument For: The N in PIN stands for Number, and the M in ATM stands for Machine.
Argument Against: Yeah, okay. But, PIN and ATM have become standalone terms these days. It's helpful to put the words "number" and "machine" to ensure everyone understands.

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