| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [v-ing] [prep] [pron] | 1004 |
|
| 2 | it is [prep] [pron] | 605 |
|
| 3 | it is [v-ing] [prep] | 539 |
|
| 4 | it is [v-ing] [pron] | 150 |
|
| 5 | it [v-ing] [prep] [pron] | 86 |
|
