| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been [verb] [adv] | 18666 |
|
| 2 | been [v-ing] [adv] | 3532 |
|
| 3 | [be] operating [adv] | 94 |
|
| 4 | be operating [adv] | 93 |
|
| 5 | been operate [adv] | 25 |
|
| 6 | [been] operating [adv] | 13 |
|
