Threw vs. Through vs. Thru: What’s the Difference?

There are a few scenarios with writing that you want to make sure you don’t use the wrong word because it’s the kind of error that gets noticed. The confusion exists because these words are homophones. They may sound the same, but they have different meanings and uses.


We can begin with the definition of each word as a starting point. Then, we’ll consider each one in detail with examples.

  • Threw: Past tense of the verb, throw, as in to hurl or propel something away
  • Through: State of being done with something or in one end and out the other as through a tunnel
  • Thru: An informal way of writing through

When To Use Threw

Perhaps the biggest challenge of using threw is to use it in the correct tense. Threw denotes a past event when referring to something that has already happened. If it has yet to occur, you’d would use the word, throw, instead.


  • He threw a great party last weekend
  • She threw away a great opportunity

When to Use Through

Through is an old word, becoming part of the English language before 900. Depending on how you use it, it can be a preposition, adverb or adjective. You’ll most likely encounter through as a preposition.

You’ll also use it as an adverb to mean the end of something. It can take on a similar meaning when you use it as an adjective.


  • Jane is through with her task
  • He completed five through nine on his to-do list
  • I read the book through, cover to cover
  • She was through with him

When to Use Thru

Thru is simply an informal way of writing through. It came into the English language in the mid-1800s with that same purpose.

It tends to lend an unpolished look to your writing that some may equate with laziness, making it inappropriate for formal writing. You should also forgo using it with authoritative pieces as it may undermine its credibility.

There are times when using thru is acceptable. In a text or email, you can get away with using it since it has an informal connotation that is appropriate in these scenarios.


  • I’ll meet you when I’m thru with work
  • Aren’t you thru yet?

Tips for Correct Usage

Using threw vs through vs thru correctly is simple if you remember a few facts. You’ll likely see thru flagged by a spellchecker making it easy to correct.

Unfortunately, that’s not always the case with threw or through, especially if you’ve spelled them right.That’s why you have to pay attention to your content.

The best way to avoid errors is to remember that threw is a verb and through is a preposition, adverb or adjective. As far as thru goes, it’s best to avoid using it at all so that it doesn’t accidentally appear in your formal writing.

Vincent D'Eletto

Vincent D'Eletto

Hey, I'm Vin. Founder and CEO of I create content that ranks really well on search engines for our clients. I'm also deeply involved with the SEO community; maintaining a portfolio of successful, profitable affiliate websites. You can find me playing guitar, drinking scotch, and hanging out with my German Shorthaired Pointer when I'm not working!