| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] for several | 87 |
|
| 2 | be [vb pp] for months | 24 |
|
| 3 | [vb pp] for several months | 21 |
|
| 4 | be [vb pp] several months | 5 |
|
