| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [v-ing] [adv] [prep] a period | 9 |
|
| 2 | [v-ing] [adv] [prep] a period | 9 |
|
| 3 | [v-ing] [adv] a [adj] period | 11 |
|
| 4 | [v-ing] [adv] a [adj] period | 10 |
|
| 5 | [v-ing] [adv] a long period | 5 |
|
| 6 | [v-ing] [adv] a period [prep] | 13 |
|
| 7 | [v-ing] [adv] a period [prep] | 13 |
|
| 8 | [v-ing] [adv] a period of | 12 |
|
| 9 | [v-ing] [adv] a period of | 12 |
|
