| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [prep] | 736 |
|
| 2 | a [adj] period [prep] [noun sg] | 570 |
|
| 3 | [prep] a period [prep] [noun sg] | 476 |
|
| 4 | [prep] a [adj] [prep] [noun sg] | 106 |
|
| 5 | [prep] a [adj] period [noun sg] | 8 |
|
