| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] have been [verb] useful | 5 |
|
| 2 | have been [verb] useful [prep] | 7 |
|
| 3 | have been [verb] useful [prep] | 7 |
|
| 4 | have been [verb] useful in | 6 |
|
| 5 | have been [verb] useful in | 6 |
|
