| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] been [v-ing] a [noun] | 439 |
|
| 2 | must [verb] been a [noun] | 181 |
|
| 3 | must [verb] been [v-ing] [noun] | 20 |
|
| 4 | must [verb] been [v-ing] a | 7 |
|
