| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have been [verb] [prep] [det] | 28 |
|
| 2 | must have [been] [verb] [prep] [det] | 28 |
|
| 3 | must have [been] [vb pp] [prep] [det] | 18 |
|
| 4 | must have [been] [v-ing] [prep] [det] | 10 |
|
| 5 | must have [been] [verb] [prep] some | 10 |
|
| 6 | must have [been] [verb] on [det] | 7 |
|
| 7 | must have [been] [verb] by [det] | 5 |
|
| 8 | must have [been] [verb] for [det] | 5 |
|
