| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who have served | 137 |
|
| 2 | who [vb past] served | 93 |
|
| 3 | who had served | 91 |
|
| 4 | who [vb -s] served | 22 |
|
| 5 | who [vb base] served | 22 |
|
| 6 | who has served | 21 |
|
| 7 | who have served | 18 |
|
