| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they had [be] [v-ing] | 307 |
|
| 2 | they [be] [v-ing] at | 277 |
|
| 3 | had [be] [v-ing] at | 148 |
|
| 4 | they had [be] at | 18 |
|
