| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh pn] [vb base] [adv] been able | 7 |
|
| 2 | [Wh pn] have [adv] been able | 7 |
|
| 3 | who [vb base] [adv] been able | 7 |
|
| 4 | [Wh pn] [vb base] [not/n't] been able | 6 |
|
| 5 | [Wh pn] [vb base] not been able | 6 |
|
