| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] [noun pl] [was/were] a period | 5 |
|
| 2 | [noun pl] [was/were] a period of | 6 |
|
| 3 | [noun pl] [was/were] a period [prep] | 6 |
|
| 4 | [noun pl] [was/were] a period of | 6 |
|
| 5 | [noun pl] [was/were] a period [prep] | 6 |
|
