5A) This table is for sale.
This is more likely to be used when it is being offered by a private seller rather than a shop.
B) This table is on sale.
This is more likely to be used if the table is in a shop. We would normally expect a little more information, such as 'from tomorrow', 'in most branches of Pummelland', etc..
C) This table may be for sale.
D) This table may be on sale.
Qn2. Is D) correct? It's OK, but, once again, we would normally expect a little more information.
Qn3. Does "on sale" means it is cheaper than normal prices? Or does it only mean that the table is available for sale?
Normally only the latter in BrE.
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