| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] sometimes [verb] | 215 |
|
| 2 | it [is] useful [verb] | 200 |
|
| 3 | it [is] sometimes useful | 16 |
|
| 4 | [is] sometimes useful [verb] | 14 |
|
