Another case of pesky homophones making English tricky, passed and past often cause problems.
Past can be an adjective, a noun, a preposition or an adverb but never a verb. And there in lies the rub. The verb pass in its past tense form is passed. The car passed by, the moment has passed, I passed you in the street yesterday.
Trouble is, this sounds a mighty lot like past, something that is gone by, or no longer existing. Past can be an adjective, a noun, a preposition, or an adverb, but never a verb. So any situation where you need to use the verb pass in its past tense remember to use passed, not past. It can help to change the sentence in to the present tense to see if the way you are using passed/past is as a verb. Like this:
‘Rain? Wind? Overcast Looks like summer has past/passed then.‘ In the present tense this sentence would be ‘Rain? Wind? Overcast? Looks like summer is passing then.’ Which shows pass is the verb being used. So it’s passed you want. Not past.
Basically, just remember, if you need to write the past tense of the verb “to pass,” use passed. Clear as mud? Excellent.