| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun sg] at a [adj] | 2667 |
|
| 2 | [noun sg] [prep] a difficult | 78 |
|
| 3 | [noun sg] [prep] a difficult | 78 |
|
| 4 | [noun sg] at [art] difficult | 10 |
|
| 5 | [noun] at a difficult | 8 |
|
| 6 | [noun sg] at a difficult | 7 |
|
