| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] [modal v] [verb] | 18418 |
|
| 2 | system [modal v] [verb] | 777 |
|
| 3 | system [Wh det] [verb] | 534 |
|
| 4 | system [Wh det] [modal v] | 138 |
|
