| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [verb] to [be] [v-ing] | 161 |
|
| 2 | could be [verb] to [be] | 153 |
|
| 3 | could be [verb] to [v-ing] | 8 |
|
| 4 | could [verb] to [be] [v-ing] | 5 |
|
