| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [verb] [prep] a | 15653 |
|
| 2 | must be [verb] [prep] | 5095 |
|
| 3 | must [verb] [prep] a | 240 |
|
| 4 | must be [prep] a | 104 |
|
| 5 | must be [verb] a | 98 |
|
