第一句：Do you have any discount for sale?
A: Excuse me. Do you have any discount for sale?
B: We do have some. Please have a look.
第二句：Do you have any on sale?
A: May I help you?
B: Do you have any on sale?
A: Those shoes are on sale.
The shirt is 30% off.
No discount for those on sale.
No discount for these off-price merchandise.