| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | useful for [v-ing] [art] | 46 |
|
| 2 | [is] useful for [v-ing] | 40 |
|
| 3 | [is] for [v-ing] [art] | 21 |
|
| 4 | [is] useful for [art] | 16 |
|
