| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | to be [vb pp] over a period | 8 |
|
| 2 | [prep] be [vb pp] over a period | 8 |
|
| 3 | [prep] be [vb pp] over a period | 8 |
|
| 4 | to be [vb pp] over a period | 8 |
|
| 5 | [modal v] be [vb pp] over a period | 7 |
|
| 6 | [vb mod] be [vb pp] over a period | 7 |
|
| 7 | be [vb pp] [adv] over a period | 7 |
|
| 8 | be [vb pp] [adv prt] over a period | 6 |
|
| 9 | be [vb pp] over a [adj] period | 21 |
|
| 10 | be [vb pp] over a [adj] period | 11 |
|
| 11 | be [vb pp] over a long period | 10 |
|
| 12 | be [vb pp] over a [adj -er] period | 10 |
|
| 13 | be [vb pp] over a longer period | 8 |
|
| 14 | be [vb pp] over a period [prep] | 15 |
|
| 15 | be [vb pp] over a period [prep] | 15 |
|
| 16 | be [vb pp] over a period of | 15 |
|
| 17 | be [vb pp] over a period of | 15 |
|
