| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [adv] [prep] a long | 82 |
|
| 2 | [adv] [prep] a long period | 36 |
|
| 3 | [vb past] [adv] [prep] a period | 10 |
|
| 4 | [vb past] [adv] a long period | 8 |
|
