| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have [be] [art] | 2989 |
|
| 2 | could [verb] [be] [art] | 475 |
|
| 3 | could [vb infin] [be] [art] | 475 |
|
| 4 | could have [be] [art] | 369 |
|
