| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pers pn] is difficult [to-vb] whether [art] | 15 |
|
| 2 | it is difficult [to-vb] whether [art] | 15 |
|
| 3 | [pron] is difficult [to-vb] whether [art] | 15 |
|
| 4 | it is difficult [to-vb] whether [art] | 15 |
|
| 5 | is [adv] difficult [to-vb] whether [art] | 8 |
|
| 6 | is [adv] difficult [to-vb] whether [art] | 8 |
|
| 7 | is difficult [to-vb] whether [art] [noun] | 10 |
|
| 8 | is difficult [to-vb] whether [art] [noun sg] | 7 |
|
