| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] useful for [v-ing] [det] [noun] | 5 |
|
| 2 | be useful for [v-ing] [det] [noun] | 5 |
|
| 3 | [be] useful for [v-ing] [det] [noun] | 5 |
|
