| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [prep] time | 297 |
|
| 2 | [prep] a long period [prep] time | 98 |
|
| 3 | [prep] a [adj -er] period [prep] time | 15 |
|
| 4 | [prep] a longer period [prep] [noun] | 12 |
|
| 5 | [prep] a longer [noun] [prep] time | 12 |
|
| 6 | [prep] a longer [noun sg] [prep] time | 12 |
|
| 7 | [prep] a longer period [prep] time | 10 |
|
| 8 | [prep] [art] longer period [prep] time | 10 |
|
