3. She hasn't celebrated her birthday for five months.
→ It's been five months since she celebrated her birthday.

4. We haven't eaten out for a month.
→ The last time we ate out was a month ago.

5. She has lived in Da Nang for five years.
→ She moved to Da Nang five years ago.

6. Mr Nam started teaching English at Dai An secondary school 4 years ago.
→ Mr Nam has been teaching English at Dai An secondary school for 4 years.

7. This is the first time Quang has herded the buffaloes.
→ Quang has never herded the buffaloes before.

8. I haven't visited my grandparents for three months.
→ The last time I visited my grandparents was three months ago.

9. I have been working in this company for at least 10 years.
→ I started working in this company at least 10 years ago.

10. It's been 3 months since I last talked to Hoa.
→ The last time I talked to Hoa was 3 months ago.