| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adv] [adj] period [conj] | 10 |
|
| 2 | [prep] a [adv] [adj -er] period [conj] | 6 |
|
| 3 | [prep] a [adv] [adj] period [coord] | 6 |
|
| 4 | [prep] a [adv] long period [conj] | 6 |
|
| 5 | [prep] a [adv] [adj] period and | 5 |
|
| 6 | [prep] a [adv] [adj] period and | 5 |
|
| 7 | [prep] a [adv] longer period [conj] | 5 |
|
