| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | not [art] period | 12 |
|
| 2 | [not/n't] [art] period | 12 |
|
| 3 | [not/n't] a period | 8 |
|
| 4 | [not/n't] a period | 8 |
|
