| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | although it [is] [adv] known | 11 |
|
| 2 | although it [is] [not/n't] known | 9 |
|
| 3 | although it [is] not known | 9 |
|
| 4 | although it [is] not known | 9 |
|
