| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could only be [vb pp] | 506 |
|
| 2 | could be [vb pp] [adj] | 239 |
|
| 3 | could only be [adj] | 40 |
|
| 4 | only be [vb pp] [adj] | 23 |
|
