| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] while [v-ing] [prep] | 7 |
|
| 2 | be while [v-ing] [prep] | 7 |
|
| 3 | [was/were] while [v-ing] [prep] | 6 |
|
| 4 | was while [v-ing] [prep] | 6 |
|
