| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [prep] [v-ing] | 2583 |
|
| 2 | it [prep] [v-ing] | 1118 |
|
| 3 | is it [prep] | 682 |
|
| 4 | is it [v-ing] | 346 |
|
