| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [v-ing] [prep] an | 31 |
|
| 2 | have been [v-ing] for an | 31 |
|
| 3 | has been [v-ing] [prep] an | 17 |
|
| 4 | have been [v-ing] to an | 8 |
|
| 5 | 'd been [v-ing] [prep] an | 7 |
|
| 6 | have been [v-ing] [prep] an | 7 |
|
| 7 | have been [v-ing] as an | 7 |
|
| 8 | have been looking [prep] an | 7 |
|
| 9 | have been [v-ing] in an | 6 |
|
| 10 | have been working [prep] an | 5 |
|
| 11 | have been waiting [prep] an | 5 |
|
