| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [v-ing] [art] [noun] | 1451 |
|
| 2 | must have been [art] [noun] | 277 |
|
| 3 | must have been [v-ing] [art] | 20 |
|
| 4 | must have been [v-ing] [noun] | 20 |
|
