| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it have been know for some | 9 |
|
| 2 | it [verb] been known for some | 9 |
|
| 3 | it [vb -s] been know for some | 8 |
|
| 4 | it has been know for some | 7 |
|
