| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | because [pron] is difficult [to-vb] | 17 |
|
| 2 | because [pron] is difficult [verb] | 17 |
|
| 3 | because it is difficult [verb] | 17 |
|
| 4 | because it is difficult [verb] | 17 |
|
| 5 | because [pers pn] is difficult [verb] | 17 |
|
