passed, past

Passed or passed is the past tense ( yesterday, or some time ago ) of "pass", meaning to get by or go by, physically, or to get an acceptable score or grade--
He passed the history exam by ten points.
We passed a gas station a few miles back.
We passed the exit!

Past or past ( rhymes with passed ) modifies or describes something that has gone by, in time or in space--
That is all past history.
Past may be used as an adverb ( describes an action) --
We drove past the exit!
He walked right past us!
Past or past may also be used as a noun ( thing or idea ), meaning the time gone by, in general, or a particular time period of years ago--
The museum has interesting relics of the past.
In the distant past, people had to walk anywhere they wanted to go.

Now that you know that, you can say--
"We just drove past the burger stand that we passed earlier. We went in a circle!"
"We passed a gas station on the highway"
"We drove past a gas station."

Note--a "pass" may mean the slip of paper an official gives someone to permit access to a building, or permission to move about in a building--
Where is your pass? Does your teacher know where you are?
Ask your teacher for a pass to visit the library.
Note # 2--To give something "a pass" means to skip it, or to decide not to participate--
We gave the new movie a pass, and went to the arcade instead
Note # 3--a person "with a past" ( usually a woman ) has a disreputable reputation--
The old biddies were sure their new neighbor was a woman with a past.
Note # 4--"pasta" ( one word ) means noodles--
Would you like a bowl of pasta?
Not to be confused with "past a " ( two words ), meaning the time gone by,  followed by the article "a" --
Do you think about the past a lot?
Or meaning having gone by something--
Did we drive past a sign?
No, we passed a truck with an ad on the side.