| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun sg] [prep] a [adj] period | 583 |
|
| 2 | [noun sg] [prep] a prolonged [noun] | 43 |
|
| 3 | [noun sg] [prep] a prolonged [noun sg] | 43 |
|
| 4 | [noun] [prep] a prolonged period | 25 |
|
| 5 | [noun sg] [prep] a prolonged period | 17 |
|
| 6 | [noun sg] [prep] [art] prolonged period | 17 |
|
