| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have been [v-ing] [prep] a | 25 |
|
| 2 | might have been [v-ing] [prep] a | 6 |
|
| 3 | [vb mod] have been [v-ing] in a | 5 |
|
| 4 | [vb mod] have been [v-ing] for a | 5 |
|
| 5 | may have been [v-ing] [prep] a | 5 |
|
| 6 | must have been [v-ing] [prep] a | 5 |
|
