| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | may [adv] have heard [prep] | 9 |
|
| 2 | may [adv] have heard of | 6 |
|
| 3 | may not have heard [prep] | 5 |
|
| 4 | may not have heard [prep] | 5 |
|
| 5 | may [not/n't] have heard [prep] | 5 |
|
