| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is useful for [verb] [noun] | 11 |
|
| 2 | [is] useful for [verb] [noun] | 11 |
|
| 3 | [is] useful for [v-ing] [noun] | 11 |
|
| 4 | [is] useful for [verb] [noun] | 11 |
|
| 5 | [is] useful for [verb] [noun pl] | 7 |
|
