English in Mind, pages 35-38
Grammar: Tag Questions
Present Perfect Tense with already, yet, just

No one thinks that free wifi is good idea. All three persons — Mike, Anna and Tim think that it’s a bad idea.

2. She has just gone to bed, but hasn’t switched the lights off yet.

3. He just bought a new bike, but he can’t ride it yet.

4. She just ate the dinner, but hadn’t done the washing-up yet.

5. He just made some fruit juice, but hadn’t drunk it yet.

6. He just scored goal, but they didn’t win yet.