| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] have been [verb] a | 917 |
|
| 2 | [pron] must have been [verb] | 371 |
|
| 3 | [pron] must have been a | 321 |
|
| 4 | [pron] must have [verb] a | 231 |
|
| 5 | must have been [verb] a | 15 |
|
