| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what have [been] [v-ing] | 191 |
|
| 2 | what have been [v-ing] | 191 |
|
| 3 | what have [been] happening | 105 |
|
| 4 | what 's [been] [v-ing] | 83 |
|
| 5 | what has [been] [v-ing] | 74 |
|
| 6 | what have [been] going | 63 |
|
| 7 | what had [been] [v-ing] | 34 |
|
