| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun sg] [prep] a period | 558 |
|
| 2 | [noun sg] [prep] a prolonged | 49 |
|
| 3 | [prep] a prolonged period | 42 |
|
| 4 | [noun sg] [prep] prolonged period | 8 |
|
