| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had once | 1105 |
|
| 2 | has once | 56 |
|
| 3 | having once | 43 |
|
| 4 | 'd once | 42 |
|
| 5 | have once | 28 |
|
| 6 | have once | 14 |
|
| 7 | to have once | 7 |
|
| 8 | 've once | 5 |
|
