| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a long period | 67 |
|
| 2 | [vb -s] [vb pp] [prep] a long | 23 |
|
| 3 | [vb -s] [vb pp] [prep] a period | 10 |
|
