| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [vb pp] [prep] a | 51403 |
|
| 2 | could [be] [vb pp] [prep] | 7114 |
|
| 3 | could [be] [vb pp] a | 90 |
|
| 4 | could [be] [prep] a | 61 |
|
