| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | this [is] often [vb pp] to | 10 |
|
| 2 | this is often [verb] to | 10 |
|
| 3 | this [is] often [verb] to | 10 |
|
| 4 | this [is] often referred to | 8 |
|
| 5 | this [is] often refer to | 8 |
|
