Passed is the past tense form of the verb to pass:
to pass: transitive verb meaning “to go beyond a point or place”
The principal parts are pass, passed, (have) passed, passing
Examples: I pass my evenings alone. Please pass the potatoes.
I am passing my days in the garden. I am passing all my courses in college.
The truck passed the house. His uncle passed away. I have passed my driving test. Charlie has passed out the papers. The cat had passed beyond the fence before we noticed she was out.
The word past can be used as more than one part of speech, but never as a verb.
past: noun meaning “that which has happened in past time.”
Ex. That’s all in the past. It’s usually preceded by the word “the.”
past: adjective meaning “gone by in time; elapsed.”
Ex. I haven’t seen him for the past month.
past: adverb meaning “beyond.” Usually the point of reference is supplied by the context.
Ex. I cowered as the bullets whizzed past.
past: preposition meaning “beyond.” It differs from an adverb because it is followed by an object.
Ex. The bullet whizzed past my head.
Two more handy tips:
The only verb that belongs in front of passed is some form of have:The days have passed quickly.
He had passed his exams before his father lost his job.
The horse has passed the finish line.
If the verb is is, don’t use passed:
For, lo, the winter is past.
Daily Writing Tips