| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [det] [noun sg] [prep] a [adj] period | 21 |
|
| 2 | [det] [noun] for a [adj] period | 15 |
|
| 3 | [det] [noun pl] [prep] a [adj] period | 14 |
|
| 4 | [det] [noun] over a [adj] period | 11 |
|
| 5 | this [noun] [prep] a [adj] period | 7 |
|
| 6 | that [noun] [prep] a [adj] period | 6 |
|
| 7 | [det] [noun] [prep] a long period | 5 |
|
