Past and passed sound exactly the same. The difference is whether you need a verb or not.

The short answer #

  • Passed is a verb, the past tense of pass: She passed the exam.
  • Past is everything else: a noun, adjective, preposition, or adverb about time or position. in the past, walk past the store

Passed = the action of passing #

  • I passed my driving test.
  • A car passed us on the highway.
  • Time passed quickly.
  • He passed the salt.

Past = time or position #

  • In the past, I wrote everything by hand. (noun)
  • The past week was busy. (adjective)
  • It's ten past five. (preposition)
  • We drove past your house. (preposition)
  • A bus just went past. (adverb)

The test #

Try changing the sentence to the present tense.

  • If the word becomes pass or passes, you need passed.
  • If it doesn't change, you need past.

We walked ___ the park. → "We walk past the park." (no change) → past

Three hours ___. → "Three hours pass." → passed

Common mistakes #

Wrong Right
I past the test! I passed the test!
The deadline has past. The deadline has passed.
That's in the passed now. That's in the past now.

Let AI decide #

AI Grammar Checker looks at how the word works in your sentence and chooses past or passed correctly.