| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had [been] [prep] [noun] | 1251 |
|
| 2 | [verb] [been] [prep] operation | 51 |
|
| 3 | have [been] [prep] operation | 51 |
|
| 4 | had [be] [prep] operation | 15 |
|
| 5 | [vb past] [been] [prep] operation | 15 |
|
