| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb base] been [verb] | 29977 |
|
| 2 | [vb base] been [v-ing] | 6806 |
|
| 3 | [verb] been operating | 92 |
|
| 4 | [vb base] been operate | 30 |
|
| 5 | [vb base] [be] operating | 23 |
|
| 6 | [vb base] [been] operating | 23 |
|
| 7 | [vb base] be operating | 23 |
|
