- We have plenty of time, don't we?
- We have plenty of time, haven't we?
Which is correct – 1 or 2?
- They have already sent you the invitation, didn't they?
- They have already sent you the invitation, haven't they?
Which is correct – 3 or 4?
Can you explain the rule by which both are correct/one of them is correct, with practical examples where we can use 'haven't'/where we can't/where we can use both?
PS: The previous post of the similar question was a little unclear with different answers by each answerer.
Best Answer
Short answer: 1 is common in American English; 2 is common in British English; 3 is uncommon in British and American English; 4 is common in British and American English.
Tag questions (American English), or question tags (British English) are often taught as simple rules, but their use is actually rather complicated.
The simple rules are:
https://en.wikipedia.org/wiki/Tag_question
According to those rules, because "we have plenty of time" is in the present simple, the correct tag would be do: "we have plenty of time, don't we?" This is the tag that's typically used in American English.
However, the common (a common?) rendering of the sentence in British English uses have as the tag: "We have plenty of time, haven't we?"
Gunnel Tottie and Sebastian Hoffman have written a very interesting study of the differences between American and British tag questions: "Tag Questions in British and American English".
Here's their summary, with added emphasis on a particularly relevant finding: