| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [adv] [prep] a period [prep] | 15 |
|
| 2 | [noun] [adv] [prep] a period [prep] | 15 |
|
| 3 | [noun] [adv] [prep] a period [prep] | 14 |
|
| 4 | [noun] [adv] [prep] a period of | 14 |
|
| 5 | [noun] [adv] [prep] a period of | 14 |
|
| 6 | [noun sg] [adv] [prep] a period [prep] | 11 |
|
| 7 | [noun] [adv] over a period [prep] | 7 |
|
| 8 | [noun] [adv] over a period [prep] | 7 |
|
