| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [verb] | 37993 |
|
| 2 | had been [v-ing] | 5819 |
|
| 3 | have been reading | 153 |
|
| 4 | [verb] been reading | 153 |
|
| 5 | had been read | 65 |
|
| 6 | [vb past] been reading | 60 |
|
| 7 | had [be] reading | 52 |
|
| 8 | had be reading | 52 |
|
| 9 | had [been] reading | 51 |
|
