| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been [v-ing] [prep] | 288 |
|
| 2 | [modal v] not have been [prep] | 67 |
|
| 3 | [modal v] not have been [v-ing] | 34 |
|
| 4 | not have been [v-ing] [prep] | 11 |
|
