| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had be [v-ing] [prep] | 1919 |
|
| 2 | [Wh pn] be [v-ing] [prep] | 1758 |
|
| 3 | [Wh pn] had be [v-ing] | 475 |
|
| 4 | [Wh pn] had be [prep] | 330 |
|
