| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | short period [prep] time | 100 |
|
| 2 | short period of time | 100 |
|
| 3 | short period of time | 100 |
|
| 4 | short period [prep] time | 94 |
|
| 5 | shorter period [prep] time | 6 |
|
