| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] be [verb] back to | 223 |
|
| 2 | [vb mod] be trace back [prep] | 91 |
|
| 3 | [vb mod] be trace back [prep] | 91 |
|
| 4 | [vb mod] be trace [adv] to | 89 |
|
| 5 | [vb mod] be trace back to | 78 |
|
| 6 | [modal v] be trace back to | 78 |
|
| 7 | [vb mod] [be] trace back to | 78 |
|
