| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they have be [v-ing] [prep] | 256 |
|
| 2 | must have be [v-ing] [prep] | 81 |
|
| 3 | they must have be [v-ing] | 19 |
|
| 4 | they must be [v-ing] [prep] | 13 |
|
| 5 | they must have be [prep] | 11 |
|
