| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a [adj] period of | 87 |
|
| 2 | [vb pp] [prep] a long [noun] of | 71 |
|
| 3 | [vb pp] [prep] a long [noun sg] of | 63 |
|
| 4 | [verb] [prep] a long period of | 34 |
|
| 5 | [vb pp] [prep] a long period [prep] | 32 |
|
| 6 | [vb pp] [prep] [art] long period of | 30 |
|
| 7 | [vb pp] [prep] [art] long period of | 30 |
|
| 8 | [vb pp] [prep] a long period of | 27 |
|
| 9 | [vb pp] [prep] a long period of | 27 |
|
