| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a period | 2137 |
|
| 2 | [prep] a period | 2137 |
|
| 3 | before a [noun] | 548 |
|
| 4 | before [art] period | 12 |
|
| 5 | before [art] period | 12 |
|
| 6 | before a period | 6 |
|
| 7 | before a period | 6 |
|
