| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [was/were] [v-ing] on | 2318 |
|
| 2 | [was/were] [v-ing] this | 387 |
|
| 3 | [v-ing] on this | 340 |
|
| 4 | [was/were] on this | 79 |
|
