I am going to present a funny gift to my friend. What is the best sentence which will describe the item? Is the following sentence correct?
Be prepared to get a gift which you never had before.
I would use this:
Be prepared to get a gift that you won't expect.
To stir up the most turmoil within the recipient, that would work. Or something like this:
Get ready for a once-in-a-lifetime gift!
It's really up to you. The sentence that you gave doesn't convey the meaning that you're trying to get across (be ready for anything) as well as the above examples, since it simply means be ready for a gift that you haven't had before, which could be something like a piece of chalk, which is not necessarily funny, but simply something they have never received. My examples do not convey the exact meaning (be ready for a funny gift) because I think that you'd be giving away too much information. A gift should be a surprise!
If you want to keep the same sentence, you just need to change the form of have to make it read Be prepared to get a gift which you’ve never had before. But a native speaker of British English would be more likely to say something like I’ve got a surprise for you. It’s a present which I bet you’ve never beeen given before.
A never-before gift. The collocation 'never before' is quite popular and widely used for dramatic effect.