| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they [modal v] have been [v-ing] [prep] | 24 |
|
| 2 | they [vb mod] have been [v-ing] [prep] | 24 |
|
| 3 | they [modal v] have been [v-ing] [prep] | 23 |
|
| 4 | they must have been [v-ing] [prep] | 6 |
|
| 5 | they must have been [v-ing] [prep] | 6 |
|
| 6 | they [modal v] have been [v-ing] for | 6 |
|
| 7 | they should have been [v-ing] [prep] | 5 |
|
| 8 | they should have been [v-ing] [prep] | 5 |
|
