| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of [noun sg] | 561 |
|
| 2 | [adv] [adj] period of [noun sg] | 133 |
|
| 3 | [adv] a [adj] period of | 42 |
|
| 4 | [adv] a period of [noun sg] | 37 |
|
| 5 | [adv] a [adj] of [noun sg] | 26 |
|
