| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] must have been [verb] [prep] | 118 |
|
| 2 | [noun] [vb mod] have been [v-ing] [prep] | 89 |
|
| 3 | [noun] [modal v] have been [v-ing] [prep] | 89 |
|
| 4 | [noun] must have been [v-ing] [prep] | 19 |
|
| 5 | [noun] must have [been] [v-ing] [prep] | 19 |
|
| 6 | [noun] must have be [v-ing] [prep] | 19 |
|
| 7 | [noun] must have [be] [v-ing] [prep] | 19 |
|
| 8 | [noun] must [verb] been [v-ing] [prep] | 19 |
|
| 9 | [noun] must have been [v-ing] [prep] | 19 |
|
