"Past" or "passed"?

Solution 1:

Past, rather than passed, is certainly what is needed here, but it’s not, as others have said, an adverb when used in this way. It’s a preposition having the store as its complement.

Solution 2:

Past definition 13 (adverb): So as to pass by or beyond.

For passed to be the correct word, you would need to say something like this:

I passed the store, then turned left.

But this:

Go past the store, then turn left.

is undoubtedly correct.

Solution 3:

It's past; it's being used as a preposition in your example. Passed is a verb (usually).

Here's an example using each one:

• We went past the mall on the way to the store.
• We passed the mall on the way to the store.
• You should go ahead and pass the slow car.
• You should go ahead and go past the slow car.