| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [verb] a useful [noun sg] | 25 |
|
| 2 | it [vb -s] a useful [noun] | 23 |
|
| 3 | it provide a useful [noun] | 8 |
|
| 4 | it provides a useful [noun] | 7 |
|
