I didn't get the following sentence straight.
- Excuse me, but can you read at all?
As far as I Know, at all used in negative statements to emphasize what you are saying.
This sentence is from a reading article as following:
Tom is an old farmer. He lives a long way from the town.One day he goes into town to buy something. After shopping, he goes into a restaurant and sits down at a table.When he looks around, he sees some old men put on their eyeglasses before reading their newspapers.
After lunch, he goes to a shop to buy glasses, too. The man in the shop makes him try on a lot of glasses, but Tom always says, "No, I can't read with these."
At last the man asks Tom, "Excuse me, but can you read at all?"
"No, I can't!" Tom says, "If I can read, do you think I will come here to buy glasses?"
My question is: Can the question the man asks Tom be rephrased to:
"Excuse me, can't you read at all?"
What is the difference between them?