| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been [verb] [adv prt] by | 41 |
|
| 2 | must have been [verb] [adv prt] [prep] | 36 |
|
| 3 | must have been [verb] [adv] by | 11 |
|
| 4 | must have [been] [verb] [adv prt] by | 6 |
|
| 5 | must [verb] been [verb] [adv prt] by | 6 |
|
| 6 | must [vb infin] been [verb] [adv prt] by | 6 |
|
| 7 | must have be [verb] [adv prt] by | 6 |
|
| 8 | must have been [verb] [adv prt] by | 6 |
|
| 9 | must have [be] [verb] [adv prt] by | 6 |
|
