| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a longer period of | 12 |
|
| 2 | [prep] a longer period of | 12 |
|
| 3 | over a longer period of | 7 |
|
| 4 | over a longer period of | 7 |
|
| 5 | [verb] a longer period of | 5 |
|
| 6 | a [adv] longer period of | 5 |
|
| 7 | a [adv] longer period of | 5 |
|
| 8 | a longer period of [noun sg] | 18 |
|
| 9 | a longer period of [noun] | 18 |
|
| 10 | a longer period of time | 13 |
|
| 11 | a longer period of time | 13 |
|
