Could/can any native english speaker tell me what the difference between 'can' and 'could' in the following sentences is. And, are they interchangeable in the following context? What Difference do the words can and could create when making a request or an offer?
Here are the examples:
Suppose, I am looking for a particular bank but I don't know where the bank is. I meet an old man and want to know the direction of the bank from him. So I ask him "Can/Could you please tell me where the bank is?"
Can/Could anyone please teach me how to share videos and photos on Facebook?
As usual, if there is anything ungrammatical in the writing, please correct it.