| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [prep] a [adj] period | 162 |
|
| 2 | [adv] [prep] a long period | 36 |
|
| 3 | [adv] [prep] a longer [noun] | 23 |
|
| 4 | [adv] [prep] a longer [noun sg] | 23 |
|
| 5 | [adv] [prep] a [adj -er] period | 9 |
|
| 6 | [adv] [prep] [art] longer period | 8 |
|
| 7 | [adv] [prep] [art] longer period | 8 |
|
| 8 | [adv] [prep] a longer period | 7 |
|
| 9 | [adv] [prep] a longer period | 7 |
|
