| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which [modal v] [verb] for [art] | 67 |
|
| 2 | [pron] [modal v] account for [art] | 39 |
|
| 3 | which [modal v] account for [art] | 23 |
|
| 4 | which [modal v] account [prep] [art] | 23 |
|
