| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] [vb pp] | 3866 |
|
| 2 | it is often [vb pp] | 362 |
|
| 3 | is [adv] often [vb pp] | 187 |
|
| 4 | it is [adv] often | 79 |
|
