| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have be [vb pp] | 495 |
|
| 2 | have be [vb pp] down | 41 |
|
| 3 | must be [vb pp] down | 24 |
|
| 4 | must have [vb pp] down | 18 |
|
