| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [v-ing] [prep] [pron] | 981 |
|
| 2 | could have been [v-ing] [prep] | 31 |
|
| 3 | could have been [prep] [pron] | 10 |
|
| 4 | could have been [v-ing] [pron] | 9 |
|
