| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [be] [v-ing] | 15837 |
|
| 2 | to [be] [v-ing] | 7573 |
|
| 3 | [modal v] to [be] | 4612 |
|
| 4 | [modal v] to [v-ing] | 21 |
|
