| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of | 842 |
|
| 2 | a long period of | 205 |
|
| 3 | a longer [noun] of | 59 |
|
| 4 | a longer [noun sg] of | 58 |
|
| 5 | a [adj -er] period of | 54 |
|
| 6 | a longer period [prep] | 29 |
|
| 7 | [art] longer period of | 23 |
|
| 8 | [art] longer period of | 23 |
|
| 9 | a longer period of | 22 |
|
| 10 | a longer period of | 22 |
|
