| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh pn] [vb past] [been] unable | 18 |
|
| 2 | [Wh pn] [vb past] been unable | 18 |
|
| 3 | [Wh pn] [vb past] be unable | 18 |
|
| 4 | who [vb past] [be] unable | 18 |
|
| 5 | [Wh pn] had [be] unable | 16 |
|
