| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be useful [prep] a [adj] [noun sg] | 16 |
|
| 2 | be useful [prep] a [adj] [noun sg] | 15 |
|
| 3 | be useful [prep] a [adj] [noun sg] | 9 |
|
| 4 | be useful as a [adj] [noun sg] | 6 |
|
| 5 | be useful as a [adj] [noun sg] | 6 |
|
| 6 | is useful [prep] a [adj] [noun sg] | 5 |
|
