| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is often [adj] [verb] [art] | 64 |
|
| 2 | it is often [adj] [to-vb] [art] | 64 |
|
| 3 | it is often [adj] [verb] [art] | 64 |
|
| 4 | it is often [adj] [verb] the | 43 |
|
| 5 | it is often [adj] [verb] the | 43 |
|
| 6 | it is often [adj] [verb] a | 20 |
|
| 7 | it is often difficult [verb] [art] | 18 |
|
| 8 | it is often [adj] [verb] a | 18 |
|
| 9 | it is often possible [verb] [art] | 16 |
|
| 10 | it is often [adj] use [art] | 6 |
|
| 11 | it is often [adj] to use [art] | 6 |
|
| 12 | it is often necessary [verb] [art] | 5 |
|
