| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [is] useful for [verb] | 40 |
|
| 2 | useful for [verb] [adv] | 29 |
|
| 3 | [is] useful [verb] [adv] | 23 |
|
| 4 | [is] for [verb] [adv] | 19 |
|
