| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a short period [prep] | 133 |
|
| 2 | a [adv] short period | 81 |
|
| 3 | [adv] short period [prep] | 67 |
|
| 4 | a [adv] short [prep] | 14 |
|
