| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [v-ing] a | 24506 |
|
| 2 | [prep] a first | 695 |
|
| 3 | [prep] [v-ing] first | 98 |
|
| 4 | [v-ing] a first | 65 |
|
