| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a [adv] [adj] period | 31 |
|
| 2 | [prep] a [adv] longer period | 21 |
|
| 3 | over a [adv] long period | 21 |
|
| 4 | over a [adv] longer [noun] | 14 |
|
| 5 | over a [adv] longer [noun sg] | 14 |
|
| 6 | over [art] [adv] longer period | 12 |
|
| 7 | over [art] [adv] longer period | 12 |
|
| 8 | over a [adv] longer period | 12 |
|
| 9 | over a [adv] [adj -er] period | 12 |
|
| 10 | over a [adv] longer period | 11 |
|
| 11 | over a [adv] longer period | 11 |
|
