Reusing the other speaker's words

Sometimes one person in a conversation echoes back words that another speaker has just used. Since the second speaker wishes to comment on this material, or to query it, naturally he accents it:

〉 I can't stand | whisky.
》 you can't stand whisky?

〉 We're having strawberries | for tea.
Ooh, | strawberries!
See discussion above,
2.16
(pardon questions, second order questions, please repeat wh questions).

Sometimes the echoed word, although repeated, nevertheless clearly conveys new information:

〉 You say your name's Smith?
Yes, | Smith.

〉 Would you like coffee or tea?
Tea, please.

〉 Was the thief tall or short?
Oh, | definitely tall.
In these examples the first speaker asks the second for information. Supplying that information involves repeating a word just used by the first speaker. Thus the same word is reused by the second speaker, and the information it conveys is new. So it has to be brought into focus. Compare:

〉 Was the thief tall or short?
》 Well ⤵⤴fairly tall.
Here, instead, the second speaker takes tallness as given and puts contrastive focus on the qualification fairly.

We can also echo the other's speaker's word and comment on them:

What three times five? Fifteen?
Fifteen, | that's right.

〉 So you're going to emigrate.
Emigrate, | yes.
In the next example, there are two possibilities for the second speaker:

⤵⤴Sorry , | I'm on a diet.

》 (i) But if you eat ⤵⤴chocolate, | how can you be on a diet?
》 (ii) But if you eat ⤵⤴chocolate, | how \can you be on a diet?
One possibility, (i), is to repeat the first speaker's accent pattern, placing the nucleus on diet. The other, (ii), is to deaccent diet as given, and to place nucleus on can.