| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is difficult [verb] [adv] [art] [noun sg] | 7 |
|
| 2 | [is] difficult [to-vb] [adv] [art] [noun sg] | 7 |
|
| 3 | [is] difficult [verb] [adv] [art] [noun sg] | 7 |
|
| 4 | [is] difficult [verb] [adv] the [noun sg] | 6 |
|
