| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it is difficult | 147 |
|
| 2 | although it [is] difficult | 36 |
|
| 3 | as it [is] difficult | 22 |
|
| 4 | because it [is] difficult | 22 |
|
| 5 | if it [is] difficult | 18 |
|
| 6 | so it [is] difficult | 17 |
|
| 7 | [subord] it 's difficult | 17 |
|
| 8 | since it [is] difficult | 16 |
|
| 9 | though it [is] difficult | 16 |
|
| 10 | while it [is] difficult | 7 |
|
| 11 | where it [is] difficult | 6 |
|
