| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb infin] be unable | 35 |
|
| 2 | [vb infin] been unable | 32 |
|
| 3 | [vb infin] [been] unable | 32 |
|
| 4 | have [be] unable | 32 |
|
