Certainly! Here are the rewritten sentences:

1. This is the **first** army course I have ever attended.
2. It has been **two months since** Matthew applied for a fully funded scholarship.
3. The kids have never joined **such** a memorable summer camp.
4. Annie hasn’t gone snorkelling in the Philippines for **a few months**.
5. The last time the singer gave a performance was **five years ago**.
6. My best friend and I have **known** each other since secondary school.
7. My older brother has worked as an accountant **since** he became my older brother.
8. Sarah hasn’t seen a gong show **since** she travelled to Da Lat with her family.
9. The Jacksons **have lived** in the south of France since 2019.
10. She **just arrived** at the campsite a few seconds ago.