| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] a short period [prep] | 15 |
|
| 2 | [vb pp] [prep] a short period [prep] | 15 |
|
| 3 | [vb pp] [prep] a short period [prep] | 13 |
|
| 4 | [vb pp] [prep] a short period of | 10 |
|
| 5 | [vb pp] [prep] a short period of | 10 |
|
| 6 | [vb pp] for a short period [prep] | 7 |
|
