| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | depending on [adv] long | 6 |
|
| 2 | [v-ing] on [Wh adv] long | 6 |
|
| 3 | [v-ing] on how long | 6 |
|
| 4 | [v-ing] on how long | 6 |
|
