Thru vs. through?

Thru is the informal American spelling of the word through. Both versions are adjectives, prepositions, or adverbs that describe how something is located, connected, completing, or moving through space or time.

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What is the difference between thru and through?

Have you ever received a text message where someone wrote “thru” instead of “through”? If so, you may have wondered if “thru” is the same thing as “through,” or if “thru” a misspelling or abbreviation.

When it comes to the differences between thru and through, the answers are simple: 

  • Thru and through have the same definition, pronunciation, and sentence usage.
  • Through is the formal spelling for Standard English.
  • Thru is the informal and alternate spelling of the word through

What does through or thru mean?

The word through is a preposition, adverb, and adjective that generally describes the placement or direction of something. For American English, thru is the alternate form of through, and it’s written for informal contexts, such as text messages, social media, or signage.

Through as a preposition

We use the prepositional form of through to describe:

1. How something moves from one side of a location to another or “into and out of” something. For example, 

“We drove through the state of New York.”
“I walked through the Empire State Building.”

2. How something continues over time to completion.

“We sat through the entire movie.”
“We lived through the pandemic.” 

3. How something inspects or observes the entirety of something. 

“Grammarians like to read through Merriam Webster’s Dictionary.”
“We read through your research paper.”
“I can see through the curtain.”

4. How something proceeds with a process or how something occurs as a result. 

“I ordered my desk through Amazon.”
“He finds support through his family.”
“I opened a business through savings and determination.”

5. How something leads or continues up to a certain point in a sequence. 

“We accept applications from January 12 through May 13.”

6. How something entered an opening or pushed through a solid surface. 

“They ran through the tunnels.” 
“She drove through five traffic signs before the police stopped her.”
“The light shines through the window.”

7. How something is positioned in several places in an area.  

“There are several animal species that live through the valley.”

Preposition synonyms

Across, along, amid, between, by means of, during, midst, throughout, via.

Through as an adverb

The adverb form of through shares a definition with the propositional form. In this case, we can use the adverb version to describe:

  1. Something that moves from one side or end to the other.
  2. Something that occurs from start to finish. 
  3. An action that occurs continuously within a period of time.
  4. How something observes all or part of something. 

The one exception occurs when the adverb through describes a connection by phone. For example, 

“Can you place a call through to the Queen?” 
“We can connect you through to the White House.”

Adverb synonyms

Around, continuously, constantly, over, throughout. 

Through as a adjective

As an adjective, we use the word through to convey completion, a direct route, or an uninterrupted path or journey to a destination. For example, 

“I am through with the relationship.”
“There’s a through road from Portland that leads to the coast.” 
“It’s a through ticket, so you don’t need a new boarding pass for the next layover.”

Adjective synonyms

Complete, concluded, done, ended, over, terminated.

Adjective antonyms

Continuing, incomplete, ongoing, undone, unfinished. 

The history of through vs. thru

The preposition and adverb form of through entered the English Language via Old English “thurh.” The same word is connected to Proto-Germanic thurx, which is from Proto-Indo-European (PIE) root ‘tere-’ for “to cross over,” “overcome,” or “pass-through.” 

While the word “thurh” didn’t change to “through” until around 1300, it’s unclear when American English began spelling “through” as “thru.” The Online Etymology Dictionary reports the term’s initial appearances around 1839 via Scottish or Yankee dialects. However, Google Books’ Ngram Viewer reports usage within English literature as early as 1579. 

When to use thru in a sentence?

Although dictionaries recognize thru as an alternate spelling of through, it’s best to avoid using it for formal situations. There are times, however, when thru is a common alternative. For example, many Americans write “thru” instead of “through” when describing a fast food restaurant’s drive-thru or a drive-thru medical service. 

Additional examples of thru for informal writing include: 

  • When are you going to come thru?” = When are you coming over? 
  • She came thru for me.” = She was there for me when I asked for help. 
  • No thru traffic.” = Vehicle traffic cannot travel on the road to a different destination.
  • High school seniors celebrate graduation with drive-thru ceremonies.” = Instead of walking on a stage, graduates pick up their diplomas through a car window. 

When to use through in a sentence?

The word through is the preferred spelling to use for informal or formal writing. The most common ways to use through in American or British English include: 

  • I’m trying to get through to you.” = I’m trying to make you understand something.
  • Let’s walk through the park.” = Let’s walk along together in the park. 
  • I’m through with you.” = I’m finished talking to you or ending a relationship. 
  • The restaurant has a drive-through.” = The restaurant serves food through a drive-up window (thru as an alternative). 
  • We broke through the wall.” = We smashed into the wall and came out on the other side. 
  • This is a through-street.” = This street leads to a final destination. 
  • We slept through the alarm clock.” = We didn’t wake up from the alarm. 

How to remember the difference between through vs thru?

The best way to remember the difference between through and thru is through a simple mnemonic. Since the word “through” is the official spelling, allow the letter o to stand for “official.” “Thru,” the informal spelling of through, only contains the letter u for “unofficial.” 

Through = O = official spelling

Thru = U = unofficial spelling

FAQ: Related to thru vs through

Do British English speakers use thru instead of through?

The shorthand use of thru over through is an American writing quirk, as sources note how thru is relatively uncommon or accepted for British English. Whether you’re in the United Kingdom or the United States, the preferred spelling is through

Are through and thru homophones?

By definition, a homophone is a set of words that have the same pronunciation but have different spelling and meanings. The words thru and through have the same meaning and definition, but they don’t share spelling. 

Therefore, thru and through are not homophones–– they are simply two versions of the same word. 

Through does have one homophone, however. The word threw is the past tense of the verb throw, and this term shares the same pronunciation as through, as well. The commonly confused words are homophones because they have separate definitions and spellings.

Additional examples of homophones include:

Test Yourself!

Think you’re ready to put your grammar skills to the test? See how much you’ve learned about thru vs through with the following multiple-choice questions. 

  1. True or false: through and thru have different meanings.
    a. True
    b. False
  2. The word __________ is not a part of formal English grammar. 
    a. Through
    b. Thru
    c. A and B
    d. None of the above
  3. The official spelling of “through” occurred when? 
    a. 1300-ish
    b. 1839
    c. 1579
    d. 1231
  4. True or false: The word thru is the correct spelling of through. 
    a. True
    b. False
  5. British English grammar rules exclude the use of __________.
    a. Threw
    b. Through
    c. Thru
    d. A and C


  1. B
  2. B
  3. A
  4. B
  5. C


  1. Through.” Cambridge Dictionary, Cambridge University Press, 2020.
  2. ThroughLexico, Oxford University Press, 2020.
  3. Through (prep., adv.)Online Etymology Dictionary, Douglas Harper, 2020. 
  4. Thru.” Lexico, Oxford University Press, 2020.
  5. Thu.” Macmillan Dictionary, Macmillan Education Limited, 2020. 
  6. Thru.” Ngram Viewer, Google Books, 2020. 
  7. Thru (prep.)Online Etymology Dictionary, Douglas Harper, 2020.