| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adv] [adj] period [prep] | 72 |
|
| 2 | [prep] a [adv] [adj] period [prep] | 72 |
|
| 3 | [prep] a [adv] [adj] period [prep] | 65 |
|
| 4 | [prep] a [adv] [adj] period of | 57 |
|
| 5 | [prep] a [adv] [adj] period of | 57 |
|
| 6 | [prep] a [adv] short period [prep] | 37 |
|
| 7 | [prep] a [adv] short period [prep] | 34 |
|
| 8 | [prep] a very [adj] period [prep] | 26 |
|
| 9 | for a [adv] [adj] period [prep] | 23 |
|
| 10 | [prep] a relatively [adj] period [prep] | 22 |
|
| 11 | in a [adv] [adj] period [prep] | 14 |
|
| 12 | [prep] a [adv] long period [prep] | 12 |
|
| 13 | [prep] a [adv] long period [prep] | 8 |
|
| 14 | [prep] a [adv] [adj] period in | 8 |
|
| 15 | over a [adv] [adj] period [prep] | 8 |
|
| 16 | [prep] a [adv] [adj] period in | 8 |
|
| 17 | [prep] a [adv] [adj -er] period [prep] | 7 |
|
| 18 | within a [adv] [adj] period [prep] | 7 |
|
| 19 | [prep] a much [adj] period [prep] | 6 |
|
