| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be at the back | 97 |
|
| 2 | was at the back | 32 |
|
| 3 | is at the back | 18 |
|
| 4 | 's at the back | 15 |
|
| 5 | were at the back | 12 |
|
| 6 | are at the back | 8 |
|
| 7 | be at the back | 7 |
|
