| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [adv] not [verb] been able | 5 |
|
| 2 | [vb mod] [adv] not [verb] been able | 5 |
|
| 3 | [adv] not [verb] been able [verb] | 5 |
|
| 4 | [adv] not [verb] been able [to-vb] | 5 |
|
