| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [be] [v-ing] a | 819 |
|
| 2 | [be] [v-ing] on a | 749 |
|
| 3 | [modal v] [be] [v-ing] on | 336 |
|
| 4 | [modal v] [be] on a | 138 |
|
