What do you say? / What are you saying? = when we don't understand

[ademoglu]

Hi,

As is seen on the page (http://idioms.thefreedictionary.com/What+do+you+say?), 'What do you say' has more than one meaning (1. Inf. Hello, how are you? 2. Lit. What is your answer or decision? 3. Lit. an expression urging a child to say Thank you or please). So I'd like to ask if we can use it when we don't understand what a person says or has just said, for example:

Friend: Beckett's 'Waiting For Godot' tells the story of two men who are ,in vain, waiting for someone named Godot, who will never arrive.
Me: (I cannot catch what he says) What do you say? / What are you saying?

I gather that they could sound OK but it is better to say 'what did (just) you say?' or something like that.

Thanks.

 

[bhaisahab]

Use "What did you (just) say?".

 

[Raymott]

As far as I know, "What do you say?" is only used before a person has said the relevant thing - as in your examples.
Here's another use.

Tom: We could go to the pub for a few drinks. What do you say?
Bob: Sure. Sounds like a plan.