| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of time | 337 |
|
| 2 | a long period of time | 115 |
|
| 3 | a [adj -er] period of time | 18 |
|
| 4 | a longer period of [noun sg] | 18 |
|
| 5 | a longer period of [noun] | 18 |
|
| 6 | a longer [noun sg] of time | 18 |
|
| 7 | a longer [noun] of time | 18 |
|
| 8 | a longer period [prep] time | 13 |
|
| 9 | a longer period of time | 13 |
|
| 10 | a longer period [prep] time | 13 |
|
| 11 | [art] longer period of time | 13 |
|
| 12 | a longer period of time | 13 |
|
| 13 | [art] longer period of time | 13 |
|
| 14 | a longer period of time | 13 |
|
| 15 | a longer period of time | 13 |
|
