| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] when a [noun sg] | 138 |
|
| 2 | [adj] when a [noun sg] | 119 |
|
| 3 | useful when [art] [noun sg] | 22 |
|
| 4 | useful when [art] [noun sg] | 22 |
|
| 5 | useful [conj] a [noun sg] | 20 |
|
| 6 | useful [subord] a [noun sg] | 18 |
|
| 7 | useful when a [noun sg] | 5 |
|
| 8 | useful when a [noun sg] | 5 |
|
| 9 | useful when a [noun] | 5 |
|
| 10 | useful when a [noun sg] | 5 |
|
