| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] [v-ing] for an | 31 |
|
| 2 | have been [v-ing] for an | 31 |
|
| 3 | had [been] [v-ing] for an | 12 |
|
| 4 | has [been] [v-ing] for an | 7 |
|
| 5 | have [been] looking for an | 7 |
|
