| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period in | 72 |
|
| 2 | [prep] a [adj] period in | 70 |
|
| 3 | for a [adj] period in | 28 |
|
| 4 | [prep] a short period in | 11 |
|
| 5 | [prep] a short period in | 11 |
|
| 6 | [prep] a brief period in | 9 |
|
| 7 | [prep] a brief period in | 9 |
|
| 8 | during a [adj] period in | 8 |
|
| 9 | after a [adj] period in | 6 |
|
| 10 | over a [adj] period in | 6 |
|
| 11 | of a [adj] period in | 6 |
|
| 12 | [prep] a long period in | 5 |
|
