| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] be [det] doubt | 166 |
|
| 2 | [modal v] be [det] doubt | 166 |
|
| 3 | could be [det] [noun] | 150 |
|
| 4 | could [be] [det] doubt | 7 |
|
| 5 | could be [det] doubt | 7 |
|
| 6 | could be [adj] doubt | 7 |
|
