| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what it [modal v] have been [prep] | 20 |
|
| 2 | what [pers pn] must have been [prep] | 15 |
|
| 3 | what [pron] must have been [prep] | 15 |
|
| 4 | [pron] it must have been [prep] | 14 |
|
| 5 | what it must have [be] [prep] | 13 |
|
| 6 | what it must have been [prep] | 13 |
|
| 7 | what it must [verb] been [prep] | 13 |
|
| 8 | what it must have [been] [prep] | 13 |
|
| 9 | what it must have been [prep] | 13 |
|
| 10 | what it must have be [prep] | 13 |
|
