| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [adv] happens [conj] | 77 |
|
| 2 | it [adv] happens [conj] | 77 |
|
| 3 | it often [verb] [conj] | 39 |
|
| 4 | it often [vb -s] [conj] | 34 |
|
| 5 | [pron] often happens [conj] | 25 |
|
| 6 | it often happens [conj] | 24 |
|
| 7 | it often happen [conj] | 24 |
|
