more than 90% of the ahvaz people cant speak english. they speak persian an arabic. if you want to buy some thing you probably have problem with seller. so you must find some one that he speak english or maybe you shoud learn persian.
Do not put anything valuable in your luggage when you travel by bus. I have heard that some even very little or no value things have been lost after the luggage has been searched at army or police checkpoints in Southern Iran.