| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a period [prep] | 2664 |
|
| 2 | [vb pp] a period | 50 |
|
| 3 | [vb pp] a [prep] | 26 |
|
| 4 | [vb pp] period [prep] | 7 |
|
