| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [vb pp] [prep] a [adj] period | 176 |
|
| 2 | [be] [vb pp] [prep] a [adj] period | 156 |
|
| 3 | [be] [vb pp] [prep] a long [noun] | 146 |
|
| 4 | [be] [vb pp] [prep] a long [noun sg] | 143 |
|
| 5 | [be] [vb pp] [prep] a long period | 34 |
|
| 6 | [be] [verb] [prep] a long period | 26 |
|
| 7 | [be] [vb pp] [prep] [art] long period | 23 |
|
| 8 | [be] [vb pp] [prep] a long period | 23 |
|
