| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [coord] it [be] [adv] difficult [verb] | 133 |
|
| 2 | [coord] it [be] [adv] difficult [verb] | 111 |
|
| 3 | [coord] it [be] often [adj] [verb] | 28 |
|
| 4 | [conj] it [be] often difficult [verb] | 25 |
|
| 5 | [coord] it [be] often [adj] [verb] | 23 |
|
| 6 | [coord] [pron] [be] often difficult [verb] | 12 |
|
| 7 | [coord] it [be] often difficult [verb] | 10 |
|
| 8 | [coord] it [be] often difficult [verb] | 10 |
|
