| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | understand what be [v-ing] to | 16 |
|
| 2 | understand what be happening to | 15 |
|
| 3 | understand what is [v-ing] to | 8 |
|
| 4 | understand what be [v-ing] to | 8 |
|
| 5 | to understand what be [v-ing] to | 7 |
|
| 6 | understand what was [v-ing] to | 6 |
|
