| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a [adj] period of | 177 |
|
| 2 | [adv] for a [adj] period | 67 |
|
| 3 | [adv] a [adj] period of | 42 |
|
| 4 | [adv] for a period of | 23 |
|
