| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a [adj] period [prep] | 272 |
|
| 2 | [vb infin] for a [adj] period | 21 |
|
| 3 | [vb infin] a [adj] period [prep] | 18 |
|
| 4 | [vb infin] for a period [prep] | 6 |
|
