Grammar Auction: Present Perfect - right or wrong? (Worksheet)

Busyteacher.org. — 1 p.
(Автор не указан).
Level: Pre-Intermediate, Intermediate.
This worksheet is intended for general revision of grammar: students read the sentences and decide if they are correct and if they aren't, they have to correct the mistakes. Then, they bid on the correct ones, of course, the teacher has to make them doubt (are you sure? who wants to bid more? great offer! and so on).