| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] a period [prep] | 117 |
|
| 2 | [adv] a period of | 110 |
|
| 3 | [adv] a period of | 110 |
|
| 4 | [adv prt] a period [prep] | 68 |
|
| 5 | over a period [prep] | 62 |
|
| 6 | over a period [prep] | 62 |
|
| 7 | [adv] a period [prep] | 41 |
|
| 8 | long a period [prep] | 7 |
|
| 9 | not a period [prep] | 7 |
|
| 10 | not a period [prep] | 7 |
|
| 11 | long a period [prep] | 7 |
|
| 12 | [not/n't] a period [prep] | 7 |
|
| 13 | also a period [prep] | 6 |
|
| 14 | also a period [prep] | 6 |
|
