| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must have been [pron] [prep] | 10 |
|
| 2 | it must have been [indef pn] [prep] | 10 |
|
| 3 | it must have been something [prep] | 5 |
|
| 4 | it must have been something [prep] | 5 |
|
