| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be useful for [v-ing] [noun pl] | 18 |
|
| 2 | be useful for [verb] [noun pl] | 18 |
|
| 3 | is useful for [verb] [noun pl] | 7 |
|
| 4 | are useful for [verb] [noun pl] | 5 |
|
| 5 | be useful for [verb] [noun pl] | 5 |
|
