1 but I haven't packed my rucksack yet.
2 Has your friend Sam picked up the tickets yet?
No, but he has already bought them.
3 Have you decided to take your phone or tablet yet?
Yes, I've just packed it.
4 Has your friend Sam booked a taxi yet?
No, he hasn't got the numbet yet.
5 Have you written down the emergency number yet?
Yes, I've just written it down on the notepaper.