# "Which number of apple looks the best?" Is "number of apple" correct to refer to the index?

Imagine having 10 items in a stack.

Which item would you like?

I'd like item number 3 as counted from the top.

No problem with this sentence. But what if I continue like this:

And you sir, which number of item would you like?

Is this last sentence correctly written? Is the `number of item` correctly used?

• If I said `number of items`, then I would be referring to the total sum. I would be refering to the number 10, because there are 10 items in the stack.

• Is it then correct to refer to a particular item inside the stack as a `number of item`?

I know that the word `index` covers this, such as in:

The index of the item I choose is 3.

But isn't the word `index` far too technical? Can I use the above `number of item` as a more colloquial way of saying it?

Some more examples:

I will decide which number/number of item/index to pick out later.

Apple number 5 looks rotten. Which number of apple looks the best?

In terms of idiomatic usage, the second form of question would not be asked:

✘ And you, sir, which number of item would you like?

It's not used because it would be thought of as an incorrectly expressed version of the following:

And you, sir, what number of items would you like?

Or, in other words, the more commonly asked:

And you, sir, how many would you like?

Note the difference in meaning.

The more common way of expressing your question and answer pairs depends on if the items are actually labelled with numbers or not.

With labels:

"And you, sir, which item number would you like?"
"I'd like item number 3."

Without labels:

"Which item would you like?"
"I'd like the third item from the top."

Note that questions and answers about items that have been labelled with numbers can draw from both groups. But items without labels are restricted to the second group.

In other words, item number only meaningfully applies if there are numbered labels.

You can use the expression number of items in the case of items that are not numbered, but that's a different context. It is asking about quantity, not selection.

The use of index is specific to a logical or mathematical domain that doesn't translate to natural language question and answer exchanges.

• I'd suggest that "Which number would you like?" is more common, with "item" implied by fact that all of the items have different numbers. Likewise, the more common response, would be, "I'd like the third from the top." Feb 21, 2019 at 18:55
• @WhatRoughBeast You could be right, but I was trying to maintain the original language (with item and number) as much as possible in order to show the difference. Feb 21, 2019 at 20:42