| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | understand why [pers pn] [verb] it | 12 |
|
| 2 | understand why [pron] [verb] it | 12 |
|
| 3 | understand why [pron] [vb past] it | 8 |
|
| 4 | understand why [pron] do it | 7 |
|
| 5 | understand why [pron] [verb] it | 7 |
|
| 6 | understand why [pron] did it | 6 |
|
