| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [is] [adv] difficult | 2051 |
|
| 2 | [is] [adv] to say | 493 |
|
| 3 | [is] difficult to say | 84 |
|
| 4 | [adv] difficult to say | 45 |
|
