| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they have n't been able | 18 |
|
| 2 | they [vb past] n't been able | 10 |
|
| 3 | they had n't been able | 10 |
|
| 4 | they [vb base] n't been able | 7 |
|
| 5 | they have n't been able | 7 |
|
