| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] [verb] [prep] [be] a | 670 |
|
| 2 | [modal v] [verb] [prep] [be] a | 670 |
|
| 3 | could [verb] [prep] [be] [art] | 58 |
|
| 4 | could [verb] [prep] [be] a | 36 |
|
| 5 | could [verb] [prep] [be] a | 36 |
|
