| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] not always be possible [to-vb] | 8 |
|
| 2 | [modal v] not always be possible [to-vb] | 8 |
|
| 3 | may not always be possible [to-vb] | 5 |
|
| 4 | may not always be possible [to-vb] | 5 |
|
