| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [conj] it [verb] | 1071 |
|
| 2 | useful [conj] it [verb] | 38 |
|
| 3 | is useful [conj] it | 14 |
|
| 4 | is useful [conj] [verb] | 8 |
|
