| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a long [noun] | 412 |
|
| 2 | [vb pp] [prep] a long [noun sg] | 403 |
|
| 3 | [vb pp] [prep] a [adj] period | 288 |
|
| 4 | [vb pp] [prep] a [adj] period | 259 |
|
| 5 | [verb] [prep] a long period | 72 |
|
| 6 | [vb pp] [prep] a long period | 67 |
|
| 7 | [vb pp] [prep] [art] long period | 54 |
|
| 8 | [vb pp] [prep] a long period | 53 |
|
