Last week, I went to a store to look for a basketball. I saw one in a glass case I liked. I talked to a salesclerk about it. He was not a native English speaker. I am going to write down our conversation below.
As I was pointing to the basketball, I asked the salesclerk, "Are you selling this basketball?
He replied, "We sell it."
I said, "I want it."
He said, "You want one."
In our conversation, I used the present continuous (selling) and he used the present simple (sell). I said: "... it" and he said: "... one".
Who was correct on the verb tense and the word choice highlighted in black?