| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [been] [verb] for | 5399 |
|
| 2 | [verb] [been] [v-ing] for | 1564 |
|
| 3 | [verb] [been] operating [prep] | 50 |
|
| 4 | [verb] [been] operate for | 15 |
|
| 5 | [verb] [be] operating for | 15 |
|
