| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [verb] [prep] a period [prep] | 170 |
|
| 2 | [be] [verb] [prep] a period [prep] | 170 |
|
| 3 | [be] [verb] [prep] a period [prep] | 170 |
|
| 4 | [be] [verb] [prep] a period of | 154 |
|
| 5 | [be] [verb] [prep] a period of | 154 |
|
| 6 | [be] [vb pp] [prep] a period [prep] | 145 |
|
| 7 | [be] [verb] [prep] a period [prep] | 57 |
|
| 8 | be [verb] [prep] a period [prep] | 57 |
|
| 9 | [was/were] [verb] [prep] a period [prep] | 51 |
|
| 10 | [be] [verb] over a period [prep] | 41 |
|
| 11 | [be] [verb] over a period [prep] | 41 |
|
| 12 | was [verb] [prep] a period [prep] | 38 |
|
| 13 | [be] [verb] for a period [prep] | 36 |
|
| 14 | [be] [verb] for a period [prep] | 36 |
|
| 15 | [is] [verb] [prep] a period [prep] | 27 |
|
| 16 | is [verb] [prep] a period [prep] | 27 |
|
| 17 | [be] [v-ing] [prep] a period [prep] | 25 |
|
| 18 | [be] [verb] by a period [prep] | 24 |
|
| 19 | [be] [verb] by a period [prep] | 24 |
|
| 20 | been [verb] [prep] a period [prep] | 23 |
|
| 21 | [been] [verb] [prep] a period [prep] | 23 |
|
| 22 | [be] followed [prep] a period [prep] | 14 |
|
| 23 | [be] follow [prep] a period [prep] | 14 |
|
| 24 | were [verb] [prep] a period [prep] | 13 |
|
| 25 | [be] [verb] within a period [prep] | 12 |
|
| 26 | [be] [verb] as a period [prep] | 12 |
|
| 27 | [be] [verb] as a period [prep] | 12 |
|
| 28 | [be] [verb] within a period [prep] | 12 |
|
| 29 | [be] [verb] through a period [prep] | 11 |
|
| 30 | [be] [verb] through a period [prep] | 11 |
|
