I agree with all of the above that this is a management issue that you should not have to solve yourself. You can make suggestions to the manager, showing initiative and willingness to find a solution but I do believe that it is up to the manager to implement any new procedures.
The best thing I can think of is to call the main store to see if there is anyone to translate.
This is a great thought. However management would have to be on board with this, schedule/coordinate with the main store for someone to be on call as a translator so that you're not willy nilly calling the store hoping that someone would be available to help out.
The FAQ poster is another very good suggestion that you can bring up with your manager.
Or possibly a business card sized type of thing that you can hand out, adding the personal apology touch of customer interaction. Something official with the *major grocery store chain* logo on it stating "WE (important that you're not singled out) apologize for any inconvenience. Please call 'this phone number' and someone will gladly help you. We strive for customer satisfaction" Not the best wording, but something along those lines.
(snip)
he wants us to ask the customer what the issue is and what the customer wants done. He wants us to solve the issue or to attempt to solve the issue. The problem is that I am not bilingual.
What is the best way to get across to him that I do not speak their language and so it is difficult for me to do that?
By 'He' I take it that's your manager, right? He wants you (all inclusive, with your co-workers) to handle the issue.
So handle it by giving him the above (and other thoughts that you might have) suggestions. Get your co-workers on board, ask them for ideas. I'm betting you're not the only non-bilingual employee and this is not solely your own problem, it affects others as well.
I strongly encourage you to approach your manager with solutions. If your manager doesn't implement any of your suggestions and puts it back on your shoulders then kick it up a notch. Since this is a *major grocery store chain* you have upper management or even HR on your side.
Your job description does not include/require a bilingual talent.
OR! LOL! Ask your manager to pay for language classes so that you can learn the Spanish language. Add in the thought of learning sign language for any hearing-impaired customers or Arabic, or Italian