| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a [adj] period | 756 |
|
| 2 | [noun prp] for a [adj] | 709 |
|
| 3 | [noun prp] for a period | 16 |
|
| 4 | [noun prp] for [adj] period | 9 |
|
