| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [prep] [verb] [conj] a | 187 |
|
| 2 | difficulty [prep] [verb] [conj] [art] | 20 |
|
| 3 | difficulty [prep] [verb] [conj] [art] | 20 |
|
| 4 | difficulty [prep] [verb] [conj] a | 10 |
|
