| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is often [verb] | 1903 |
|
| 2 | is often [vb pp] | 1861 |
|
| 3 | is [adv] referred | 209 |
|
| 4 | is [adv] referred | 203 |
|
| 5 | [be] often referred | 93 |
|
| 6 | be often referred | 93 |
|
| 7 | [is] often referred | 50 |
|
| 8 | is often referred | 49 |
|
| 9 | is often refer | 49 |
|
