| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | there must have [been] [prep] | 13 |
|
| 2 | there must have [be] [prep] | 13 |
|
| 3 | there must have been [prep] | 13 |
|
| 4 | there must have be [prep] | 13 |
|
| 5 | there must have [be] [prep] | 13 |
|
| 6 | there must have [be] at | 8 |
|
| 7 | there must have [be] at | 8 |
|
