| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [prep] | 824 |
|
| 2 | [prep] a [adj] period [prep] | 773 |
|
| 3 | [prep] a [adj] period of | 618 |
|
| 4 | for a [adj] period [prep] | 320 |
|
| 5 | over a [adj] period [prep] | 183 |
|
| 6 | [prep] a long period [prep] | 179 |
|
| 7 | [prep] a long period [prep] | 162 |
|
| 8 | [prep] an [adj] period [prep] | 98 |
|
| 9 | [prep] a short period [prep] | 97 |
|
| 10 | [prep] a short period [prep] | 91 |
|
| 11 | after a [adj] period [prep] | 87 |
|
| 12 | [prep] a [adj] period in | 83 |
|
| 13 | [prep] a [adj -er] period [prep] | 46 |
|
| 14 | of a [adj] period [prep] | 44 |
|
| 15 | within a [adj] period [prep] | 41 |
|
| 16 | [prep] a brief period [prep] | 36 |
|
| 17 | [prep] a brief period [prep] | 36 |
|
| 18 | in a [adj] period [prep] | 36 |
|
| 19 | during a [adj] period [prep] | 30 |
|
| 20 | [prep] a fixed period [prep] | 29 |
|
| 21 | [prep] a fixed period [prep] | 29 |
|
| 22 | to a [adj] period [prep] | 25 |
|
| 23 | [prep] a certain period [prep] | 22 |
|
| 24 | [prep] a certain period [prep] | 22 |
|
| 25 | [prep] a limited period [prep] | 21 |
|
| 26 | [prep] a limited period [prep] | 21 |
|
| 27 | [prep] a [adj] period after | 21 |
|
| 28 | with a [adj] period [prep] | 21 |
|
| 29 | [prep] a considerable period [prep] | 20 |
|
| 30 | [prep] a specified period [prep] | 20 |
|
