| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] was a period | 29 |
|
| 2 | [num] [was/were] a period | 19 |
|
| 3 | [det] [was/were] a period | 18 |
|
| 4 | this [was/were] a period | 18 |
|
| 5 | this [was/were] a period | 18 |
|
| 6 | [adj] were a period | 9 |
|
