| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a [adj] period [prep] | 272 |
|
| 2 | [adv] for a [adj] period | 67 |
|
| 3 | [adv] a [adj] period [prep] | 53 |
|
| 4 | [adv] for a period [prep] | 26 |
|
