| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] over a period [prep] | 60 |
|
| 2 | [vb past] over a period [prep] | 19 |
|
| 3 | [v-ing] over a period [prep] | 13 |
|
| 4 | [vb -s] over a period [prep] | 8 |
|
| 5 | [to-vb] over a period [prep] | 6 |
|
| 6 | [vb base] over a period [prep] | 6 |
|
| 7 | occur over a period [prep] | 5 |
|
| 8 | [vb infin] over a period [prep] | 5 |
|
| 9 | extend over a period [prep] | 5 |
|
| 10 | over a [adj] period [prep] | 19 |
|
| 11 | over a [adj] period [prep] | 19 |
|
| 12 | over a long period [prep] | 9 |
|
| 13 | over a long period [prep] | 9 |
|
| 14 | over a period [prep] [adj] | 28 |
|
| 15 | over a period [prep] [noun] | 25 |
|
| 16 | over a period [prep] [num] | 23 |
|
| 17 | over a period [prep] [noun sg] | 16 |
|
| 18 | over a period [prep] time | 16 |
|
| 19 | over a period [prep] time | 16 |
|
| 20 | over a period [prep] [noun pl] | 9 |
|
| 21 | over a period [prep] [det] | 5 |
|
