| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | not [verb] [verb] heard of | 5 |
|
| 2 | not [verb] to have heard [prep] | 5 |
|
| 3 | not [verb] [to-vb] heard [prep] | 5 |
|
| 4 | not [verb] have heard [prep] | 5 |
|
