| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pers pn] must have been [prep] this | 7 |
|
| 2 | [pron] must have been [prep] this | 7 |
|
| 3 | it must have been [prep] this | 5 |
|
| 4 | it must have been [prep] this | 5 |
|
| 5 | must have been [prep] this [noun sg] | 5 |
|
| 6 | must have been [prep] this [noun] | 5 |
|
