| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who [vb past] been at the | 20 |
|
| 2 | who [vb past] [been] at the | 20 |
|
| 3 | who [vb past] be at the | 20 |
|
| 4 | who had [be] at the | 19 |
|
