| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [verb] | 62 |
|
| 2 | for a [adj] period [verb] | 24 |
|
| 3 | for a [adj] period [verb] | 24 |
|
| 4 | over a [adj] period [verb] | 22 |
|
| 5 | over a [adj] period [verb] | 22 |
|
| 6 | [prep] a [adj] period [v-ing] | 19 |
|
| 7 | [prep] a [adj] period [to-vb] | 16 |
|
| 8 | [prep] a [adj] period [vb past] | 11 |
|
| 9 | [prep] a long period [verb] | 9 |
|
| 10 | [prep] a [adj] period have | 8 |
|
| 11 | [prep] a [adj] period [vb -s] | 8 |
|
| 12 | [prep] a [adj] period [vb pp] | 6 |
|
| 13 | [prep] a three-year period [verb] | 5 |
|
