| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | useful for [adj] [noun pl] | 56 |
|
| 2 | useful for [adj] [noun sg] | 39 |
|
| 3 | useful for [adj] purposes | 6 |
|
| 4 | useful for [adj] purpose | 6 |
|
