| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] be going on in | 8 |
|
| 2 | [vb past] been going on in | 8 |
|
| 3 | [vb past] [been] going on in | 8 |
|
| 4 | had [be] going on in | 8 |
|
