| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a [adj] period [prep] | 272 |
|
| 2 | [vb past] a [adj] period [prep] | 43 |
|
| 3 | [vb past] for a [adj] period | 9 |
|
| 4 | [vb past] for a period [prep] | 5 |
|
