| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a [adj] period | 266 |
|
| 2 | [vb pp] [prep] a long period | 67 |
|
| 3 | [vb pp] [prep] a longer [noun] | 28 |
|
| 4 | [vb pp] [prep] a longer [noun sg] | 27 |
|
| 5 | [vb pp] [prep] a [adj -er] period | 26 |
|
| 6 | [verb] [prep] a longer period | 19 |
|
| 7 | [vb pp] [prep] [art] longer period | 14 |
|
| 8 | [vb pp] [prep] a longer period | 14 |
|
| 9 | [vb pp] [prep] [art] longer period | 14 |
|
| 10 | [vb pp] [prep] a longer period | 14 |
|
| 11 | [vb pp] [prep] a longer period | 14 |
|
