| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] [noun] period [prep] | 62 |
|
| 2 | [prep] a four [noun] [noun] [prep] | 31 |
|
| 3 | [prep] a four [noun] [noun sg] [prep] | 31 |
|
| 4 | [prep] a four [noun] period [prep] | 6 |
|
| 5 | [prep] a four [noun] period [prep] | 6 |
|
| 6 | [prep] [art] four [noun] period [prep] | 6 |
|
| 7 | [prep] a four [noun] period [prep] | 6 |
|
| 8 | [prep] [art] four [noun] period [prep] | 6 |
|
