| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what had been [verb] [prep] | 88 |
|
| 2 | what have been happening [prep] | 55 |
|
| 3 | what [verb] been happening [prep] | 55 |
|
| 4 | what had been [v-ing] [prep] | 11 |
|
| 5 | what had been happen [prep] | 7 |
|
| 6 | what had be happening [prep] | 7 |
|
| 7 | what had [be] happening [prep] | 7 |
|
| 8 | [pron] had been happening [prep] | 7 |
|
| 9 | what had [been] happening [prep] | 7 |
|
| 10 | what [vb past] been happening [prep] | 7 |
|
