| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] [be] | 7500 |
|
| 2 | [adv] [be] [v-ing] | 3810 |
|
| 3 | could [be] [v-ing] | 655 |
|
| 4 | could [adv] [v-ing] | 12 |
|
