| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | so [pers pn] must have been [v-ing] | 5 |
|
| 2 | so [pers pn] must have be [v-ing] | 5 |
|
| 3 | so [pers pn] must have be [v-ing] | 5 |
|
