| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] [be] useful to | 7 |
|
| 2 | [prep] [be] [adv] useful to | 7 |
|
| 3 | [prep] [be] [adv] useful to | 7 |
|
| 4 | [prep] [be] useful to [art] | 5 |
|
| 5 | [prep] [be] useful to [art] | 5 |
|
