| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] not be obtained [prep] | 21 |
|
| 2 | can not be obtained [prep] | 15 |
|
| 3 | can not be obtained [prep] | 15 |
|
| 4 | [modal v] not be obtained by | 7 |
|
| 5 | could not be obtained [prep] | 5 |
|
| 6 | could not be obtained [prep] | 5 |
|
